Julian Huppert, Lilian Greenwood, Robert Goodwill and John Humphrys at The Times's London headquarters

The roads minister rebuffed calls from cycle safety campaigners yesterday to lower the default city speed limit from 30mph to 20mph.

The major parties clashed in a special hustings on improving cycle safety hosted at The Times’s London headquarters.

Robert Goodwill, the Conservative transport minister, was pitted against Lilian Greenwood, Labour’s shadow transport minister, and Julian Huppert, the Liberal Democrat MP.

The panel, chaired by John Humphrys, the presenter, and assembled by the UK Cycling Alliance, was asked about calls to make 20mph the default speed limit in built-up areas. Research from the RAC found that 20mph zones can reduce road casualties by around 60 per cent.

Mr Goodwill said that local authorities already had it in their power to introduce 20mph zones