Blame for the security breach was initially turned on G4S and OCS, the private security firms paid to guard ministers, MPs and thousands of delegates at the Manchester Central venue.
But police sources say the Tory party itself is responsible for “fit and proper person’s checks” on prospective delegates registering to attend on its website.
“That is supposed to check that person’s character and any reputational issues,” a source said.
“Once the party is happy that person has passed they send it to the national accreditation team and police conduct criminal record checks.”
Minor offences that do not result in prosecution, like Simon Brodkin’s cautions after previous stunts, would not be sufficient for police to refuse entry on security grounds.
Greater Manchester Police confirmed the professional prankster, who performs under the name Lee Nelson, had legitimate accreditation, and announced a joint review of the process with the Conservative Party.
A representative for the comedian said he applied for his pass “independently and in his own name”, which would have revealed his occupation and track record with a cursory internet search.
Amber Rudd made no admission regarding her party’s alleged culpability during a heated interview where she repeatedly refused to explain how Mr Brodkin was let into the conference.
“We will look into that and we will do that at pace,” the Home Secretary told the BBC. “I’m not going to comment on the ongoing investigation around that man.
“It was a security breach, it is disappointing and we are looking into it.”
Greg Clark, the Business Secretary, called on his party to investigate the incident.
“That could have been someone with violent intent,” he told BBC Radio 4’s Today programme.
“I don’t know which part of the weakness of the system it was but it clearly needs to be established.
“We need to look into it and find out what happened and make sure it can never happen again.”
Mr Brodkin posed as a professional photographer to get within inches of Theresa May during her keynote conference speech, putting down his camera to hand the Prime Minister a P45.
In bizarre scenes broadcast on live television, he then managed to approach Boris Johnson – the man he claimed the fake tax form was from – before being removed.
Mr Brodkin was escorted out of the hall by a private security guard following the stunt, as Tory members shouted “Out! Out! Out!”.
He was arrested and handcuffed by police “to prevent a breach of the peace” and released a short time later.
Viewers were stunned by the security breach, with one MP remarking the comedian “could have been a terrorist”.
Angela Rayner, Labour’s Shadow Education Secretary, asked where the Prime Minister’s security team was during the debacle, adding: “We are supposed to be on high alert after recent events.”
“If the Conservatives cannot organise their own security how can they be trusted with ours?” one commenter asked.
George Freeman, a Conservative who heads the Prime Minister’s policy board, said: “There should be some very serious questions – that could have been a terrorist…questions will be asked about how he was allowed to get that close.”
Mr Brodkin’s success exposed a gap in a multi-layered security operation that was meant to be tightened in light of increased terror threat against the UK.
Greater Manchester Police mounted a protection operation around the convention centre costing an estimated £2m, seeing roads closed, cars searched, snipers stationed on surrounding rooftops and 1,000 uniformed and covert officers drafted in.
The next layer of protection was entrusted to the embattled security firm G4S, which checked delegates’ accreditation using existing lists at the perimeter and controlled airport-style scans.
Another private company, OCS, was charged with internal security for the conference, and guarding of the Prime Minister herself is the responsibility of the Met’s Royalty and Specialist Protection unit.
A former member of the highly trained squad, Steve Park, said officers were not quick enough to act as Mr Brodkin approached.
“Regardless if someone low-level has got through vetting checks, in the few seconds he moved from within the photographers it should have been a decision to say, ‘We need to remove him’,” he told The Independent.
“I’m not saying there should have been a use of force but it certainly would have necessitated a couple of close protection officers.”
The security analyst, who now trains close protection officers, noted that Mr Brodkin was within inches of the Prime Minister for several seconds and was then able to approach cabinet members.
“My feeling is that the security has fallen short – why did we need photographers quite so close to the podium in between the cabinet and Prime Minister?” he asked.
Mr Parks said that despite the increased security measures at the venue, close protection officers should have maintained the level of security required for Mrs May elsewhere.
“Multi-level security. I don’t think there’s a problem as long as everybody is working together and it’s cohesive,” he said. “At the end of the day there would be approximately 500 people in that building, most of which will be unknown.”
“It’s farcical,” he added. “I think there’s a clear error… there is a massive flaw in the vetting system from the Conservatives’ point of view.
“That layered approach is there to find all sorts of information about people you don’t want and if someone has lied or appears to be fraudulent that loophole has got to be closed.”
Chief Superintendent John O’Hare confirmed Mr Brodkin had legitimate accreditation that granted him access to the conference.
“In light of this we will be reviewing the accreditation process with the Conservative Party,” he added.
“Even with accreditation, everyone at the conference goes through airport-style searches before being allowed entry to the site.”
A spokesperson for the Conservative Party confirmed the review was underway without providing details, adding: “In light of the arrest during the Prime Minister’s speech we are working with the police to review the accreditation process and security arrangements for party conference.”
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