It’s crunch time for parties across the political spectrum: will parliamentarians do the right thing for our climate and the UK economy or will they let the sceptics drive investors overseas?

The Energy Bill returns to the Commons next week, just as the Conservatives are retreating to their traditional political stomping grounds in the face of competition from the right. Writing in Lib Dem Voice last month, Nick Clegg noted that: “Compassionate conservatism has been sidelined…the blue team used to claim to have gone green, yet have now publicly denounced the importance of environmental protections”. It’s up to the Liberal Democrats to reassert our commitment to the green principles that delivered us into Government in the first place, while showing that the setting of a decarbonisation target helps us deliver the stronger economy in a fairer society that we are determined to achieve.

Decarbonising the energy generated in this country is not just an obsession for tree-huggers, it’s also important to hard-headed pragmatists who shape the investment priorities for companies and markets. It is inarguable that the UK’s green economy has continued to grow even whilst broader economic activity has remained subdued. The CBI has demonstrated that over a third of the UK’s economic growth last year is likely to have come from green business. BIS figures in turn show average growth of 6% and the creation of 6,000 new jobs each year for this portion of the economy. These very same ‘green shoots’ are now placed at risk by a worrying lack of investor certainty; a problem that a 2030 decarbonisation target[1] would help remedy.

Organisations as diverse as EDF, Friends of the Earth, Asda, the Energy Saving Trust, Pepsico, the TUC and Microsoft have called on the Chancellor to support such a target. Our own Ed Davey – the Secretary of State for Energy and Climate Change – has explained that a ‘vast majority’ of companies in the UK want a decarbonising target for the electricity sector and that only ‘one or two’ companies do not. It is crucial that we do not wait until it is too late – as the Chancellor is proposing – to set the decarbonisation target investors need. The consequence is they will simply choose to go elsewhere, taking funds to other countries with a clearer, more ambitious policy framework.

Not only does the absence of a 2030 target risk damaging one of the fastest growing sectors of our economy, it also increases the exposure of UK consumers to the higher bills and volatility of energy supply that a greater reliance on imported gas

would bring. Or we opt for low carbon, which the Government’s own Committee on Climate Change said this week would save consumers £25-45 billion, rising to £100 billion with higher gas and carbon prices.

A 2030 decarbonisation target for power has also been shown to be a key factor in ensuring we meet our legally binding commitments to cut carbon by 2050[2] in the cheapest way possible. In other words, without a 2030 target to bridge the gap, meeting our 2050 targets will be a lot harder and lot more costly.

The Liberal Democrats have a record to be proud of on green issues; including an otherwise strong Energy Bill, promoting green transport, delivering a green investment bank and ensuring a strong level of Government ambition on climate change policy in Europe.

Let me be clear. I don’t take anything away from the work of our colleague Ed Davey (and Chris Huhne before him). He has done a brilliant job negotiating many concessions from a reluctant Tory Party who have a phalanx of flat earth society climate change deniers hogging its backbench (and, I suspect, one in the Treasury)! The Energy Bill is a credit to Ed’s work and I don’t want to do anything which might provoke a George Osborne backlash.

However, I needn’t remind Lib Dem MPs that 2030 decarb target is official Lib Dem policy. It is now left to the Liberal Democrats in Parliament to help take the lead where Ed and Nick have left off, and support the cross-party amendments on Tuesday 4^th June that would see a 2030 target included in the Bill. To do otherwise would be a disservice to our Party’s core principles and one of the key reasons we came into Government: to deliver an economically and environmentally prosperous society that will do our children proud.

* Andrew George was Liberal Democrat MP for St Ives until May 2015.