A cup of coffee could land Conservative byelection campaigners in hot water after they were accused of corrupt practices.

Tory candidates fighting a double council byelection in Coombe Vale offered the caffeine-filled beverages to voters attending public meetings with their candidates and Zac Goldsmith MP.

And while Tories maintain they asked for nothing in return for the coffees, Liberal Democrats believe the offer could breach the Representation of the People Act.

The act outlaws providing drink “for the purpose of corruptly influencing that person or any other person to vote or refrain from voting”.

But a Kingston police spokesman said they would not be investigating the matter.

Lib Dem agent Roger Hayes said he would raise the matter with the returning officer in an effort to be “helpful”, and prevent Conservatives making more “errors”.

He said: “Coffee and cake sounds like a very nice and neighbourly practice, but at times of an election it is a corrupt and illegal practice and you are just not allowed to do it.”

Tory election agent Alex Wright said they had not asked for anything in return for the refreshments.

He said: “We don’t believe we were in any breach at all.

“We want to focus on the by-election and local issues for local people. If they want to spend their time on this, that’s their choice.”