Susan Kramer and Zac Goldsmith used a hustings at Tiffin Girls’ School last night to call for the grammar school to change its selection policy to give preference to local children who meet their academic criteria.

Speaking before an audience containing many students, parents and teachers, the Liberal Democrat and Conservative parliamentary candidates won a smattering of applause after saying the current policy left many parents frustrated their children could not get into their nearest school.

Ms Kramer said: "I would really like the school to look at the alternative for families who know they live next to a wonderful school but, because of the way the choice is made, their children have very little chance of getting in there."

The candidates clashed about the future of Kingston Hospital, with Mr Goldsmith and Labour hopeful Eleanor Tunnicliffe accusing Lib Dems of making up the threat for electoral purposes, but Ms Kramer pledging to step up the campaign after the election.

Comedian Andy Parsons, from BBC comedy Mock the Week, got the biggest laugh of the night, deadpanning that he "heard a rumour they were trying to close Tiffin Girls’ down, so I think we should form a campaign to make sure that never happens."

Asked about reform of the political system, Mr Goldsmith said his first act of rebellion if elected could be to vote against a Conservative pledge to reduce the number MPs, fearing it would damage the link between voters and MPs, while Mrs Kramer pressed for a more proportional voting system.

Green party candidate James Page voiced his opposition to academy schools and the "Tesco-isation" of education.

Neither UKIP candidate Peter Dul nor independent candidate Charles Hill were invited to the debate, and handed out leaflets to members of the audience outside.