Ipswich Conservative Association has been fined £1,100 by the Electoral Commission after taking an “impermissible donation” during the run-up to last year’s general election.

The Commission said the Association was given £3,000 on March 24 last year – but because the donor was not on any electoral roll it should not have been accepted under strict rules about party political funding.

An Electoral Commission statement said: “The donor appeared to be eligible to be on the register of electors at the time the donation was received and the Commission did not seek forfeiture.

“The Commission imposed the penalty because the association did not conduct adequate checks on the donation.”

A spokesman for the commission said it was the responsibility of the party to check that the donation was allowed – it was not for the donor to check electoral law before it was given.

The Association paid the fine as soon as it was imposed, but it was not required to return the donation.

Former Ipswich council leader Liz Harsant was chairman of the Ipswich Conservative Association at the time the donation and said the issue had been a mix-up which everyone regretted.

She said: “It was a terrible mistake. It was an oversight and should have been picked up but wasn’t.

“The donor was moving home at the time so was not on any electoral role. We should have checked it more thoroughly.”

Mrs Harsant said she had been busy campaigning at the time and had thought others had checked the credentials of donors – but accepted responsibility as chair of the association at the time.

“This has been going on for months and I am very sorry about it,” she said.

Mrs Harsant stood down as chair of the Association after the election – but said she had given her successor, Guy Jenkinson, advice about always checking every donation to the party.