Jeremy Corbyn has refused to link Russia directly to the Salisbury nerve agent attack as his spokesman pointed out previous “problematic” intelligence blunders on Iraqi weapons of mass destruction (WMD).

The Labour leader sparked angry reactions from Tory MPs as he insisted that the UK should follow the evidence and share samples of the Soviet-era poisons with Russia to prove its case.

Amid angry scenes in the Commons, Corbyn described Tory jeers as “pathetic” and even attacked the Conservatives for cuts to the diplomatic service over the years.

His spokesman went further, suggesting that the material used against former spy Sergei Skripal and his daughter could have “ended up in random hands” during the break-up of the former Soviet Union.

The senior aide told reporters: “There is a history in relation to weapons of mass destruction and intelligence which are problematic, to put it mildly.”

Theresa May, when told of the comments, said in the Commons that they were “quite wrong and outrageous”.

The Prime Minister had told MPs that in the absence of a response from Moscow, there was “no alternative conclusion” than that the Russian state was “culpable” for the attempted murder.

But Corbyn’s spokemsan said that Corbyn felt that May had herself failed to rule out the possibility that the nerve agent had been used by someone other than a Russian state operative.

“The second option, that the Russian government lost control of weapons-grade nerve agents…carries with it a series of different possibilities of who might have been responsible for that.

“And the break up of the Soviet state led to all sorts of material ending up in random hands.”

He added that Russia should “comply immediately” with requests for cooperation, but said a careful “rules-based” approach was needed.

“The overwhelming evidence points to the two alternatives that the Government has set out. In the meantime, it’s essential that we follow the evidence and what that evidence produces.”

The spokesman revealed the Labour leader had received security briefings and suggested he was sceptical of what had been presented so far directly linking Putin’s regime to the attack.

Asked by HuffPost if the Labour didn’t trust the UK intelligence agencies in the wake of Iraq, the spokesman replied: “No, that’s not the issue. 

“If you remember back to the WMD saga there was both what was actually produced by the intelligence services – which in the end we had access to – and then there was how that was used in the public domain in politics. So there is a history of problems in relation to interpreting that evidence.”

He added that Corbyn had a long history of appearing isolated on foreign policy only to be proved right later.

Asked about the criticism of Labour MPs for his reluctance to side with May, he said: “In these kinds of crises, there are often initial reactions which aren’t necessarily later backed up by reality or fact.

“Jeremy’s record in relation to the judgement on internationally related crises is probably better than anyone else in the House of Commons.

“He’s been proved to make the right call time and again over the last 15 to 20 years when many others made the wrong call and some of those calls had disastrous consequences.”

When news filtered out of the spokesman’s remarks, Tory MP Alec Shelbrooke raised it with the PM.

She replied: “I am surprised and shocked at the statement that has been put out buy the spokesman for the leader of the Opposition. 

“It is very clear from the remarks that have been made by backbenchers from the Labour Party they will be equally concerned by that remark.”

And when pushed further by Tory Sleaford MP Caroline Johnson, May said: “What we are talking about here in the UK, is the use of a chemical weapon, a nerve agent, a military grade nerve agent, against people here in the UK.

That is very clear. And I think it is quite wrong and outrageous that the leader of the Opposition’s spokesman has made the comments in relation to this he has.”

In the Commons earlier, Corbyn said the attempted murder of Sergei Skripal and his daughter was a “dreadful, appalling act which we totally condemn”.

But the Labour leader said it was a matter of “huge regret” that there had been cuts of 25% to the UK’s diplomatic service in the last five years.

He questioned what May was doing to establish whether it was “still a possibility that Russia negligently lost control” of its nerve agent.

And he asked the prime minister how she had responded “to the Russian government’s request for a sample of the agent used in the Sailsibury attack to run its own tests” 

No.10 later said while there was an option of sharing its evidence with Russia under the Organisation for the Prohibition of Chemical Weapons convention, “there is no requirement to do so”.

Tory MPs, including Boris Johnson, loudly heckled Corbyn as he spoke for failing to offer enough support to the prime minister.

Corbyn told the foreign secretary his barracking across the Commons chamber “demeans his office”.

May angrily told Corbyn he was out of step with Labour MPs and others.

“It is clear from the conversations I have had with allies that we have a consensus with our allies, it was clear from the remarks that were made by backbenchers across the whole of this House on Monday that there is a consensus across the backbenches of this House,” she said.

“I am only sorry that the consensus does not go as far as the Right Honourable Gentleman who could have taken the opportunity – as the UK Government has done – to condemn the culpability of the Russian state.”

Corbyn told the prime minister her criticism of him was “pathetic” as she spoke.

Yvette Cooper, the Labour chairman of the Commons Home Affairs Committee, said the Russian actions must be met with “unequivocal condemnation”.

Conservative MPs interpreted Cooper’s comments as aimed at Corbyn and met them with cheers.

Former Labour leadership candidate Liz Kendall said she “fully supports the government’s actions”.

John Woodcock, the Labour MP for Barrow and Furness, said the Commons should “speak as one for the nation” in response to Russia.

In a swipe at Corbyn, he added: “She will be reassured to hear a clear majority of Labour MPs, alongside the leaders of every other party, support the firm stance she is taking.”

Rhondda MP Chris Bryant told MPs: “I completely support everything the prime minister has said today.”

DUP MP Sammy Wilson accused Corbyn of pursuing a “policy of appeasement” with Russia.

Conservative backbencher Anna Soubry said Corbyn’s response had been “shameful”. 

And Tory MP Mark Francois attacked Corbyn for not being able to “bring himself to condemn Russia for this outrageous act”.

“He simply couldn’t do it. And is that not because he remains at heart what he as alway been – a CND badge wearing apologist for the Russian state.”