Ken Livingstone has apologised "unreservedly" after suggesting a shadow minister suffering from depression needed psychiatric help.

The former London mayor repeatedly refused to say sorry to Kevan Jones for calling him "disturbed" as bitter divisions erupted over Labour's defence policy, and insisted he was not to blame for the ensuing row.

But Mr Livingstone later took to Twitter to say sorry amid a furious backlash from MPs and demands from Jeremy Corbyn, a close ally, that he must apologise.

He said: "I unreservedly apologise to Kevan Jones for my comments. They should not have been made at all, let alone in this context.

"I also make this apology because Jeremy is right to insist on a more civil politics and as a party we should take this seriously."

The row was triggered when Mr Jones claimed putting the opponent of nuclear weapons in joint charge of the defence policy review alongside shadow defence secretary Maria Eagle would damage Labour's credibility.

Mr Livingstone hit back at the criticism, telling the Mirror the MP should "pop off" to see his GP.

"I think he might need some psychiatric help. He's obviously very depressed and disturbed," he said. "He should pop off and see his GP before he makes these offensive comments."

Mr Jones, who said the comments belonged in the "dark ages", appeared to be unimpressed by the apology, tweeting "what about apologising to other thousands of people he insulted".

Shadow minister for mental health Luciana Berger said: "An individual's mental health should never be the excuse for insults, jibes or political point-scoring. These comments should be treated as seriously as racism or sexism."

Labour's John Woodcock said the comments were "unacceptable" and he should "withdraw and say sorry" but former MP George Galloway claimed Mr Livingstone was the victim of a witch-hunt.

He said: "The witch-hunt turns on Ken Livingstone. Tooth by tooth, claw by claw they are trying to defang JC (Jeremy Corbyn). I defend Ken."

In a TV interview earlier this week, Mr Livingstone said Ms Eagle was "mad" for backing the head of the Armed Forces in a public row about Mr Corbyn's stance on nuclear weapons.

Mr Corbyn complained after General Sir Nick Houghton said he would "worry" if a politician who was committed to not using nuclear weapons won power, as it would undermine their deterrent value. But Ms Eagle said she saw nothing wrong with the comment.

Speaking to Russia Today on Monday, Mr Livingstone said: "She's mad if she really believes that."

He added: "Most Labour MPs don't actually believe that Trident's worth spending £20 billion on. They just worry that it will be the Tory press demonising us as pro-Russian or weaklings and things like that. It's not a serious rational judgment. Twenty billion pounds - that's going to be about £1,000 in tax for every family in Britain."

Liberal Democrat Health spokesman Norman Lamb said: "It is deeply disappointing that Ken Livingstone has made such ignorant comments. For a public figure to make remarks like these is not only disrespectful to Mr Jones, but to every individual who has been affected by mental ill health.

"Remarks like this set back progress in tackling the stigma around mental health which can prevent people from accessing support when they need it."