Sadiq Khan today laid out the the difference between him and Tory Zac Goldsmith, as Labour’s London mayoral candidate launched a new ad campaign based around his pledge to freeze transport fares.

Khan has said that he will freeze all Transport for London fares – covering the tube system and buses in the capital – until 2020, while under Goldsmith’s plans some Londoners will face paying over £1,000 a month more.

He revealed the new ad campaign, which appears to pastiche the Tories’ own efforts, highlighting the policy difference between the two candidates:

Speaking at the launch this morning, Khan said:

“Londoners face a crystal clear choice on fares: a four-year fares freeze if I’m Mayor – so you won’t pay a penny more in 2020 than you do today. Or a 17 per cent rise under Zac Goldsmith – costing you up to £1,000 more.

“I know what I would choose.”

This comes as Goldsmith’s campaign comes under increasing fire in a race row that has dogged the Tories in the London Mayor contest – with David Cameron now being dragged into it.

The Prime Minister has sent out a letter targeted at Gujarati Hindu and Punjabi Sikh voters in London on behalf of Goldsmith, which has been met with criticisms of racial profiling and seeking to stoke community divisions.

The letter follows criticisms of other senior Tories on similar grounds. Michael Fallon accused Khan of speaking “alongside extremists”, while Goldsmith’s own description of Khan as “radical” has been seen by some as racially-motivated.