Meet Britain's top 50 entrepreneurs and investors who have the connections, guile and wealth to prosper in both the good times and bad.

1.Jeremy Leggett, CEO, Solar Century

This seasoned eco-warrior decided that campaigning, writing books and commentating in the national and international press on why we need a cleaner, greener planet wasn’t enough, so he decided to make a real contribution himself by setting up renewable energy venture Solar Century.

‘Many clients have got beyond the uncertainty barrier about whether the technology works and questions about whether it is good value. There are enough projects out there and installations in place for people to see that this technology works really well. It’s dead simple and good value, and that value will increase over time,’ says Leggett.

This award-winning, venture capital-backed company keeps on growing at a rate of knots and turnover is in excess of £30 million. Leggett’s vision is clear for the next five years: ‘We want to be the number one brand in building integrated solar thermal and photovoltaic technology’.

A trained geologist who turned his back on the oil industry to join Greenpeace, Leggett has become a pivotal figure between businesses and governments in the ongoing battle for a renewable revolution (see page 24). ‘It’s all about how quickly we can accelerate this inevitability. There is a massive chance for visionary politicians to lead,’ he says.

2.Ben Holmes, partner, Index Venture

Keen tennis player Holmes served up an ace by overseeing the sale of gaming company Playfish to Electronic Arts for up to $400 million (£240 million) in November. ‘The investment holding period was about 14 months and I was in discussions with them for about a year and a half beforehand,’ says Holmes, who took a board seat as co-investor (Accel Partners was the other backer).

With around €800 million (£700 million) spread across two funds, Index remains the star investor on the European venture capital stage. Unlike some of its competitors, Holmes says the firm was ‘well capitalised’ going into 2009, so there was no need to slow down the pace of new investments. Sectors such as mobile and the cloud are on his radar, while he believes e-commerce companies will continue to outperform more traditional retail businesses. ‘We are in a period of pretty significant technological change,’ he says.

As for exits, Holmes is hopeful that the market for initial public offerings (IPOs) will open up ‘in the next year or so’, and that there will be other trade buyers like Electronic Arts on the prowl for smart, disruptive businesses.

3. David Hall, managing director of private equity, YFM

YFM remains the most active investor in deals of up to £2 million, according to research from Bureau van Dijk and Business XL, and that is set to continue. ‘We have plenty of money to invest between 2010 and 2012, and we will be increasing our level of investment over that time,’ say Hall. Through its various vehicles, which include venture capital trusts, government-backed regional funds and the stand-alone Chandos Fund, YFM has invested in more than 250 businesses around the UK, with early-stage concerns making up about two-thirds of this number.

4. George Coelho, MD and head of venture capital, Good Energies

Backed by the wealthy Brenninkmeijer family, Good Energies is a force to be reckoned with in the renewable energy space. Coelho heads the venture division in Europe and the US and oversaw more than a dozen investments last year, plus the sale of Concentrix Solar to Soitec for €55 million. ‘This is the right time for green and I could be doing a deal a month, there is so much going on,’ observes Coelho, who must be the envy of other VCs when it comes to raising funds. ‘I don’t know what we have in total as I just ask for what I need,’ he says.

5. Robin Klein, founding partner, The Accelerator Group

Serial investor Robin Klein set up The Accelerator Group (TAG) with son Saul, a partner at Index Ventures. They focus almost exclusively on start-up and early-stage internet businesses, with a ‘sweet spot’ for investment of around £100,000. ‘For us, this is a real business,’ says Klein. ‘We don’t approach it like your typical angel who puts a little bit of money to work – it’s something we are dedicated to and are passionate about.’ TAG’s record speaks for itself.

Its first success (‘the one that kept us in business through the first dot-bomb’, says Klein) was Lastminute.com. It’s also had interests in Last.fm (sold for $280 million), Dopplr (snapped up by Nokia last year) and Agent Provocateur (bought by 3i for £60 million). The current portfolio includes movie rental star LoveFilm, consumer lending business Wonga (see page 57) and giant-slaying specs supplier Glasses Direct. Of 64 businesses backed by TAG in its ten-year history, four have been home runs (returns of ten times money or better), three tripled the Kleins’ investment and 15 were failures, while 42 are still active.

The Kleins also run Seedcamp, a start-up mentoring and funding programme that has been going for three years. ‘It’s just part of our attempt to replicate what they do so brilliantly in the Valley,’ says Klein. ‘We very much see London as the hub of the European tech scene.’

6.Tim Smit, CEO, The Eden Project

Courting controversy and dividing opinion, Dutch-born Tim Smit claims his Eden Project has brought £1 billion into the Cornish economy since the green tourist attraction was founded at the turn of the millennium, on top of what it spends with local suppliers. While steering clear of overt political affiliations, the former music producer believes passionately in the power of social enterprise to change communities and business, and he is one of the government’s social enterprise ambassadors (along with the likes of Big Issue founder John Bird). Not content with that, he pioneered the Sexy Green Car Show and recently entered a partnership with the government of the Maldives ‘to help it become the world’s first carbon-neutral country’.

Smit is a firm believer that ‘the overwhelming respect that is handed to the City of London is fantastically damaging’ and loathes the defeatist approach towards the UK’s manufacturing industry, advocating further government borrowing to ensure the UK becomes a world leader in low-carbon technologies.

7. Wol Kolade, managing partner, ISIS Private Equity

‘There are not many people around who understand how to operate in a low-growth environment,’ says Kolade. ‘The last time we had this was from 1990 to 1996, when there was very little real growth. Actually, it was a more interesting period, because you don’t have people sucked into competing with you [so a business can gain significant market share].’

ISIS has around £650 million of funds under management and scored a respectable exit in 2009 after UnitedHealth Group, a US-quoted global health business, acquired ScriptSwitch. For Kolade, a cautious approach will be the order of the day this year: ‘We won’t go back to 2007 levels of investment for some time. The recovery will be slow and steady, rather than a sudden upswing.’

8. Anne Glover, co-founder, Amadeus Capital Partners

One of a handful of female VCs, Glover is the leading light of Amadeus Capital Partners. The firm is a little more than halfway through investing its latest £162 million fund, and has started to work with portfolio companies with a view to exit. ‘We’ve seen underlying growth in all our companies except one that was focusing on financial services,’ says Glover, who adds that IPOs may be on the horizon towards the second half of this year.

There’s been progress at printed electronics innovator Plastic Logic which launched its first product, the Que Reader, in Las Vegas in December, while fuel efficiency specialist GreenRoad, based on ‘Israeli technology run out of California whose main market is the UK’, has won some important contracts. Amadeus did three new deals last year, while it continues to invest from its £20 million seed fund. ‘We are staying committed to seed, which very few VC investors are,’ adds Glover.

9. Simon Cook, CEO, DFJ Esprit

Under Cook’s stewardship, DFJ Esprit is steadily building its credentials as a serious player on the European venture capital stage. At the end of last year, the firm said it aims to raise €150 million for its third fund, DFJ III, while also announcing the formation of Encore Ventures, which entailed taking over the European venture portfolio of 3i in a fund sized at up to £170 million.

10. Gervais Williams, head of UK smaller companies, Gartmore

A star of the small-cap scene, Williams manages the £200 million Gartmore UK and Irish Smaller Companies Fund and the £100 million Fledgling investment trust, which focuses on the minnows of the full list. Despite last year’s rally, he says valuations of smaller companies are still ‘pitiful’.

‘We’re heading into a prolonged period when economic growth will be modest and there will be little opportunity to get decent earnings growth on the Main Market,’ he says. ‘The opportunities some small companies have to expand in spite of the low rate of growth in the economy will attract further capital.’

To see all 50 of the most influential entrepreneurs and investors in the UK, go to M&A's sister website growthbusiness.co.uk by clicking here