An advert for the British National Party published in the South Wales Evening Post in the run-up to yesterday's elections has incensed journalists there.

They believe it undermined their credibility and reporting of issues surrounding the BNP.

The 1/8th of a page electoral advert was published on Tuesday and was only spotted by a sub minutes before the paper went to print.

But staff were told that it was legal and paid for as part of the election and could not be dropped.

Unhappy editorial staff have e-mailed management to voice their concerns, and have urged union members in Wales to contact the paper to complain.

An e-mail sent to the TUC, T&G and amicus, asked as many people as possible to write a letter to the paper in a bid lobby its letters page, and also to complain directly to the editor.

The e-mail read: "Journalists at the South Wales Evening Post were incensed when they found out that the paper had accepted a paid-for election advert from the BNP. Protests were lodged with senior management and questions were asked about why it had been accepted.

"The journalists were told that as it was legal and paid for as part of the election it could not be stopped and that anyone who wanted to complain should take it up with the editor.

"Everyone is incensed that we only found out about it only a few hours before publication - close to the end of a shift for many people and after much of the paper had been laid out - and had no effective means of challenging it at that stage."

It added: "In particular many journalists rightly feel that it undermines their journalistic credibility and reporting of these issues. It will certainly lower the standing of the paper in the eyes of many people in Swansea."

Lawrence Shaw, new media and Wales assistant organiser for the National Union of Journalists, said the union had been contacted about the advert late on Monday night.

He said: "There is a strong feeling that this is not just another political party, but one that works against the principles of a free press and democracy.

"Journalists are angry that the South Wales Evening Post appears to take money from anyone, regardless of the consequences and who it might offend."

Editor Spencer Feeney was away on holiday at the time, but told HoldtheFrontPage he had been fully involved in the decision to accept the advert.

He declined to say whether he had received complaints from journalists, saying he would not comment on internal staff matters.

But he said the paper had had lots of letters and e-mails of complaints from readers.

A full pages of comments was due to be published today, all objecting to the advert.

He added that there had be a lot of debate prior to accepting the advert.

He said: "The first thing we did was send it to the lawyers to ask if there was any legal reason not to accept the advert.

"The lawyers came back and said there was not so if we had said no it would have been on personal grounds.

"The position we decided to take, after lots of thought, was that the advert was legal and from a legitamate party in as much as they were allowed to put candidates forward for election.

"The Post firmly stands for freedom of speech.

"I fully understand why lots of people find it offensive and that's why we have given them the opportunity to voice their opinion about it."

He added: "I'm sure there are lots of people or organisations which some readers feel strongly about, but I think I would still come to the same conclusion provided it was not breaking the law or inciting anyone to break the law."