Liberal Democrats have laughed off allegations they ran a homophobic campaign to win the Grove ward by-election last night.

Candidate Adrian Amer, who fellow Conservatives said was gay, lost by just 23 votes to Liberal Democrat Rebekah Moll after a recount.

A Lib Dem leaflet used on the doorsteps said: "It's always a straight fight here in Grove ward."

Ben Summerskill of gay rights group Stonewall tweeted: "Shocking news coming in about things whispered on doorsteps in Kingston Council by-election".

Simon Hughes, deputy leader of the Liberal Democrat party, apologised in 2006 for anti-gay smears in the 1983 general election where literature described as "the straight choice" against Peter Tatchell.

He later came out.

Matthew Sephton, chairman of LGBTory, the Conservative Party’s LGBT group, told the Conservative Home website: "I am shocked to hear the allegations of homophobic campaigning in this week’s Kingston by-election and I urge the Liberal Democrats to look into this matter further.

"Talk of a ‘straight fight’ or a ‘straight choice’ in such a campaign is at best insensitive and at worst a poor veil for blatant prejudice."

But leader of Kingston's Liberal Democrat Derek Osbourne, laughed when presented with the allegation.

He said: "There will be a lot of people roaring with laughter about this. It is nonsense.

"I doubt any of us knew he was gay.

"It is just an expression that we use in our leaflets and have been using for a long time – because it is a two horse race. Homophobic? Bizarre beyond belief."

Rebekah Moll said: "It feels out of the blue and it feels wrong to cast this.

"It is a shame that this has happened and that it was construed that way."

Mr Amer was unavailable for comment this morning.

His party colleague Councillor Andrea Craig said: "We did not say anything in our campaign about Adrian’s sexuality because it is not relevant but I cannot definitely say that that is not the message [in the leaflet].

"I would love to say it was but it is not something that can be proven.

"If it was [homophobic] it would be despicable. It will come out quickly if this is the case."

A spokesman for the Liberal Democrat national party said in a statement: "The Liberal Democrats have a long and proud record of fighting for LGBT+ rights. In the Coalition Government we are working to deliver equal marriage and promote equality around the world.

"Today we are flying the pride flag above the Cabinet Office, the first time it has flown on Whitehall.

"There was no intention whatsoever to use the word straight in a way which could be seen as derogatory to a gay candidate.

This is a phrase used in campaign literature across the country, regardless of sexuality, by all parties.

“Sexuality is, and should be, completely irrelevant in political campaigning. And Liberal Democrats completely abhor campaigning which could be interpreted as offensive.

“The ‘straight choice’ leaflets from the 1980s were wrong and offensive.

"The party has made it clear to all our campaigners that such language is not acceptable in our campaigns and has taken clear action where it has crossed the line."

Was the campaign homophobic? Call the newsdesk on 0208 744 4244.