Diane Abbott today claimed Jeremy Corbyn has been proved right in questioning Vladimir Putin’s responsibility for the Salisbury attack.
The shadow home secretary said Labour’s ‘thoughtful’ approach to the crisis had been borne out after Porton Down said it could not prove where the Novichok used to poison Sergei Skripal has been made.
Ms Abbott said the security services and the Prime Minister had been careful to caveat their language but condemned Boris Johnson for making ‘categorical’ claims scientists had already proved where the substance was from.
The Foreign Office deleted a Tweet making a similar claim this afternoon as a row over the details of the investigation threatened to hand a propaganda coup to the Kremlin.
Putin has already seized on Porton Down’s announcement it knew what was used to attack Mr Skripal but not its origins to demand an apology from Britain.
Diane Abbott (file image) today claimed Jeremy Corbyn has been proved right in questioning Vladimir Putin’s responsibility for the Salisbury attack
Jeremy Corbyn (pictured today in Watford) has been widely criticised for appearing cautious to blame the Kremlin for the attack on Sergei Skripal

Boris Johnson made the claim Porton Down Scientists had told him Russia was to blame in an interview on German TV on March 20 (pictured)

Sergei Skripal with his daughter Yulia before they were poisoned in Salisbury
Any suggestion Britain has overclaimed on its investigation will fuel Russian propaganda.
International allies including the EU rallied round Britain today, insisting there was other intelligence which left them convinced Russia was to blame.
Ms Abbott told the Today programme she hoped Labour will ‘get some credit for taking a more thoughtful approach and asking the right questions’.
She said: ‘It doesn’t surprise me Porton Down is saying this because the security services were always very cautious in what they said.
‘What surprised me was that so many were willing to rush into the media and say it was unequivocally Putin. That’s not necessarily what we were told.’
Told Prime Minister Theresa May did not say this, Ms Abbott replied: ‘She didn’t say that, she was quite careful in her initial statement.
‘But Boris Johnson apparently going on international media and saying he was 101% certain it was Putin – I don’t understand where he got that information from.’
Speaking today on a visit to Watford, Mr Corbyn said: ‘Boris Johnson seems to have completely exceeded the information that he had been given and told the world in categorical terms what he believed had happened.
‘And it’s not backed up by the evidence he claimed to have got from Porton Down in the first place. Boris Johnson needs to answer some questions …
‘Where does that leave the foreign secretary? Egg on his face for the statement he made on German television.’

Gary Aitkenhead, Porton Down’s chief executive, dismissed Russian claims that the nerve agent used in Salisbury might have come from the defence laboratory
‘Either the Foreign Secretary has information that he’s not sharing with Porton Down or it was a bit of exaggeration.’
Mr Johnson made the controversial claim in an interview on German TV on March 20.
Asked why the UK believed that Russia was the source of the nerve agent, Mr Johnson said: ‘The people from Porton Down, the laboratory, they were absolutely categorical.
‘I asked them that myself. I said ”Are you sure?”. He said ”There’s no doubt”.’
Commenting on Mr Johnson’s interview, a Government spokesman said: ‘The Foreign Secretary was making clear that Porton Down were sure it was a Novichok – a point they have reinforced.
‘He goes on in the same interview to make clear why based on that information, additional intelligence and the lack of alternative explanation from the Russians, we have reached the conclusion we have.

The Foreign Office deleted a Tweet making a similar claim this afternoon as a row over the details of the investigation threatened to hand a propaganda coup to the Kremlin
‘What the Foreign Secretary said then, and what Porton Down have said recently, is fully consistent with what we have said throughout. It is Russia that is putting forward multiple versions of events and obfuscating the truth.’
A message stating that Porton Down had established that the Novichok nerve agent came from Russia was deleted from the Foreign Office Twitter feed.
The tweet, issued on March 22, said: ‘Analysis by world-leading experts at the Defence Science and Technology Laboratory at Porton Down made clear that this was a military-grade Novichok nerve agent produced in Russia.’
Despite the confusion, the EU issued a strong statement of support for the UK at a meeting of chemical weapons experts today.
A statement said: ‘We have full confidence in the UK investigation and laud UK’s collaboration with the OPCW Technical Secretariat, in full compliance with the convention.’