Guy Hands, one of the City's most flamboyant deal-makers, warns on Monday that the Ukraine crisis has underlined the importance of the UK's renewable energy sector, and attacks those wanting to phase out onshore wind subsidies.

The financier, who has close links to the Conservative party, says energy security cannot be achieved by markets alone and that the government needs to play a decisive role. "We should be grateful to President Putin for bringing energy security back to the top of the political agenda in Europe. But it is up to us to ensure we understand and act on the long-term threat. And that is certainly not by turning our backs on renewable energy, no matter how persistent or loud the voices against it," Hands argues in an article on the Guardian website.

The intervention by Hands, who runs the Terra Firma private equity firm, comes at a time when instability in Crimea has been used as a major argument in favour of shale gas – most notably by a House of Lords committee last week.

Hands, whose best man at his wedding was the foreign secretary, William Hague, expresses astonishment that there has been speculation the Tory election manifesto could contain a commitment to end financial help for onshore wind, given it is the "most affordable" of all green power technologies.

Hands's Terra Firma invests in onshore wind but also landfill gas and other green schemes through a business called Infinis. The financier said Vladimir Putin's actions in Crimea had done Britain an indirect favour by putting energy security at the top of the agenda.

"We have a large industry of successful and enterprising renewable energy businesses which are ready to rise to the challenge of powering homes and businesses from clean and sustainable sources. But politicians are being pressed by a coalition of opponents of renewable energy to ignore this potential."

He argues that the subsidy debate has been dominated by those who believe energy is a market like any other, and that all efforts should be focused on prices.

"This is nonsense. Energy is not just another commodity but the lifeblood of an economy. No responsible government can step away from a market which is at the heart of a nation's security and prosperity. Security of supply as well as affordability are critical. So too are environmental impact and public acceptance."