The long-awaited Energy Bill will be published at the beginning of November and will give Ed Davey a unique opportunity to prove that Lib Dems are the greenest of the main political parties. But in the innermost circles of the Coalition Government a battle royal is currently being played out over crucial details of the text.

This bill will establish the Electricity Market Reform (EMR) that will shape UK energy policy for decades to come. It therefore offers a once-in-a-generation opportunity to set the parameters for tackling climate change, the greatest challenge of the twenty-first century. The bill also offers a real opportunity to get the British economy back on track by fostering green growth and jobs and slashing the billions we pay annually to countries likeQatarandRussiafor oil and gas imports.

The green economy is already responsible for 8 per cent of UK GDP, more than either the telecommunications or the car industries. Uniquely, the green economy has continued to grow even in the current recession and accounted for more than a third of all UK growth last year. It has created almost a million jobs in the UK, most in regions of high unemployment outside London and the South East.

But what the industry urgently needs in order to build on this great record is long-term policy certainty. This is the message UK energy companies stressed to Ed Davey over and over again during the Brighton Conference. Therefore it is crucial that the Energy Bill includes a binding 2030 target for decarbonising the power sector. Such a target would make companies secure in the knowledge that low carbon generation was here to stay – and would thereby make the sector very attractive to investors. It would also boost confidence for supply chain manufacturers and for infrastructure developers such as port authorities, for whom 2030 is tomorrow in terms of making decisions about expansion.

The Government’s main expert body on climate change, the Climate Change Committee, endorses the need for a decarbonisation target and has said that it needs to be 50g of CO2 per kWh. Lib Dems also endorsed a target in the range of 50 to 100g of CO2 per KWh at the Brighton Conference in September.

The decarbonisation target, if put into primary legislation, will ensure that the UK stays committed to its climate obligations and becomes a world leader in low carbon technology. For the greenest government ever there is no other option.

* Fiona Hall is Leader of the UK Liberal Democrat Delegation in the European Parliament and MEP for the North East of England.