Former Labour chief whip Nick Brown will stand down at the next election after he was suspended from the party after an undisclosed complaint was made against him.

The MP for Newcastle upon Tyne East hit out at the complaints process as “fundamentally and inexcusably flawed” as he confirmed that with a “heavy heart” he had decided not to stand for re-election.

It was announced on September 7 last year that Mr Brown, who was first elected to the Commons in 1983, had been suspended from the party and the whip removed.

The nature of the complaint against Mr Brown has never been disclosed.

The accusations against me were, and remain, entirely false, without even the faintest germ of any truth to them

In a lengthy statement, the MP said he would also be resigning his Labour membership.

He said: “My constituency border is now being redrawn following the national constituency boundary changes and I think it is a sensible time for me to retire – given that I would otherwise be nearly 80 by the end of my next term.

“However, it is also important to make clear that my decision to stand down is made against the backdrop of a long-running internal Labour Party disciplinary process against me – a process which I consider (and am advised) is so fundamentally, and inexcusably, flawed that I can no longer engage with it.”

The 73-year-old was made Opposition chief whip in 2016 by then-party leader Jeremy Corbyn.

Mr Brown retained the role when Sir Keir succeeded Mr Corbyn in 2020 but was moved aside a year later.

He was administratively suspended from membership of the Labour Party in the middle of last year after an investigation started.

The move led to the automatic precautionary suspension of the whip.

In the statement, released through law firm Carter-Ruck, Mr Brown said: “My suspension followed a complaint against me by a political rival within the party. It concerned an allegation about events said to have taken place more than 25 years ago.

The Labour Party has established an independent complaints process that ensures complaints are decided impartially and fairly

“The accusations against me were, and remain, entirely false, without even the faintest germ of any truth to them. Not only had they never previously been made in the ensuing 25 years, they had never been so much as hinted at, whether by that individual or anyone else.

“They came entirely out of the blue, and as a complete bombshell to me.”

He said that over the last 17 months it had become clear that he can have “no faith whatsoever” in his party’s ability to “investigate and then adjudicate on this allegation fairly and even-handedly”.

A Labour spokeswoman said: “The Labour Party treats all complaints with the utmost seriousness.

​​”The Labour Party has established an independent complaints process that ensures complaints ​are decided impartially and fairly.”