Liberal Democrats kept to that pledge. Under the leadership of the Secretary of State for Energy and Climate Change Ed Davey, they have consistently acted to make this country cleaner, greener and more open to investment in renewables. Some £37 billion has been invested in renewable energy, supporting 460,000 jobs as of 2013, reducing our carbon emissions and improving Britain's energy security.

They go on to highlight that it really was the Liberal Democrats who were responsible for the good things done in this parliament:

We have been impressed with the determination of Liberal Democrat Ministers to fight for the environment agenda - even when they met significant resistance. Their efforts to preserve the UK's natural environment and maintain its biodiversity include planting over a million trees to investing in our coastal paths, establishing 27 Marine Conservation Zones up and down the English coastline, cleaning up over 9,700 miles of rivers and 410 square miles of lakes and estuaries, and introducing a 5p charge on plastic bags from large firms.

We also welcome the prominence the Liberal Democrats have given to these issues in their manifesto vision for the next Government - notably their proposed programme of 5 Green Laws on the front page of their manifesto.

Why do they want the Liberal Democrats in the next government?

With the polls showing that another hung Parliament is likely, we hope - for the sake of the battle against climate change and for our environment - that any Coalition will include the Liberal Democrats. The Lib Dems can secure Britain's progress towards a clean energy future and ensure that our country will continue to play a leading international role on the green agenda.

A couple of the signatories are very familiar - former Scottish Liberal Democrat leader and current peer Nicol Stephen, for a start and Susan Juned, but it is still a very significant endorsement from a highly important business sector.