Jeremy Corbyn has again refused to directly blame Russia for the Salisbury nerve agent attack, urging the Government not to rush ahead of the evidence.
In an article for The Guardian, he says Theresa May must remain calm and measured in what is, he says, a fevered parliamentary atmosphere.
Mr Corbyn writes: Labour is of course no supporter of the Putin regime, its conservative authoritarianism, abuse of human rights or political and economic corruption.
But he adds: That does not mean we should resign ourselves to a new cold war of escalating arms spending, proxy conflicts across the globe and a McCarthyite intolerance of dissent.
His words will spark further fury among some of his backbenchers who openly disagreed with their leader after his comments in the Commons on Wednesday.
There is growing tension and uneasiness among many within Labour about his response to the attack.
A group of Labour MPs led by John Woodcock have defied their leader and tabled a motion offering their support for the Government’s expulsion of 23 Russian diplomats.
Mr Corbyn says he supports the actions taken by Theresa May, but would only back further sanctions as and when the investigation into the Salisbury attack produces results.
The Labour leader has said he believes the evidence points towards Russia but his repeated reluctance to point the finger of blame directly at Moscow is angering and concerning many within Labour.
There is a clear divide between Jeremy Corbyn’s office and those in the party who struggle with his position on national security and foreign policy.
And it is a division Conservative MPs are keen to exploit in the aftermath of the Salisbury attack.
Tensions within the Labour Party come as a Sky Data poll reveals that 57% of Britons say Jeremy Corbyn is doing a bad job dealing with Russia.
Just 18% believe he is doing a good job on the issue.