The Liberal Democrats will launch a green tax campaign at their annual party conference, highlighting a plan to shift the tax burden on families to environmental charges.

Sir Menzies Campbell, leader of the LibDems, has made ‘green’ taxation the heart of his struggle with Labour and the Conservatives.

Tax plans - to be debated at the party's conference – would mean environmental taxes would rise by £8bn a year to fund significant cuts in income tax for families.

Greater green taxes would come from a sharp increase in the tax on aviation as well as sharp increases in car tax on the most polluting vehicles, especially 4X4s.

Addressing a rally of party activists over the weekend Sir Menzies declared that the party's environmental tax policies were ‘the most radical ever from any major UK political party’.