Tim Farron would ban the sale of new diesel cars, legalise cannabis and reverse benefit cuts if the Liberal Democrats are elected, the party's manifesto states.

By 2025 the party would prevent any new diesel cars and small vans from being sold in the UK in a bid to curb harmful emissions which cause poor air quality.

A diesel scrappage scheme for old cars would also be introduced in order to take existing models off the road and 10 new cities would introduce low emission zones with charges for driving within a certain area.

Mr Farron, the party leader, will launch the manifesto formally later today at a venue in London.

He will set out his plan to make the Lib Dems the new opposition party and warn that Labour is not capable of holding Theresa May to account on Brexit or spending.