Tory ministers today blamed the threat of a new Salisbury-style attack for slowing down the system after issuing just 500 visas to Ukrainians since Friday.
Immigration Minister Kevin Foster said people in Calais are "pretending to be Ukrainian" with false documents in a bid to smuggle themselves into the UK.
And he raised the threat of a repeat of the 2018 poisoning with the nerve agent Novichok.
Mr Foster claimed it was the reason why the Home Office has failed to act sooner for families in the French port - with a centre in Lille, 70 miles away, expected to set up and running within 24 hours.
But he was barracked by MPs including Tories, who lined up to say the Ukraine Family Scheme was simply too slow.
SNP MP Stuart C McDonald fumed: "Don’t quote Salisbury at us. That has absolutely nothing to do with this."
Tory MP Andrew Murrison added: “Salisbury borders my constituency. I fully accept the need for security checks, particularly on adult males.
"But the fact remains that Ireland, with which we share a common travel area, has a population of 5million but has committed to 100,000 refugees from Ukraine and has admitted already over 2,000. This country, population 67million, has come nowhere even close to that. Why not?”
DUP MP Ian Paisley Jr said: “Where is the Christian compassion that this nation was known for?” Tory MP Steve Brine added: “So much about this doesn’t feel right and my constituents know what they see. All of this is far too robotic, and there’s very little Christian compassion being shown at the moment. Surely we are past the UK saying we’re going to have a generous scheme - it’s time to deliver a generous scheme.”
Tory MP Alec Shelbrooke said: “I’m proud of my constituents who are coming forward to offer as much help as possible. I’m proud of the Prime Minister in the way he is leading the world. But the Home Office is cutting off their legs. And it is simply not good enough. Does the Home Office recognise that this is a war of the likes that’s not been seen for 80 years?”
He added: “This is a disgrace… Get a grip!”
It came as Mr Foster confirmed 500 Ukraine Family Scheme visas have now been issued by the UK, up from 300 yesterday and a disputed figure of 50 on Sunday morning.
Two million have fled Ukraine, according to the United Nations refugee agency.
Tory MP Caroline Nokes said: “Snails also move ‘at pace’." And Tory MP Roger Gale suggested Priti Patel should resign.
He said: “The Home Secretary said ‘I have already made it clear in terms of the visa application centre that has now been set up en route to Calais, that we have staff in Calais.’ That was untrue. And under any normal administration, that in itself would be a resignation issue.”
Sir Roger demanded a full visa waiver scheme to allow those with Ukrainian passports to come to the UK “now”.
Tory MP Tracy Crouch said there were no available appointments at the UK’s application centre in Rzeszow, Poland until ”the end of next month".
Anatoliy Chepiga, 41, and Alexander Mishkin, 43, were charged in 2018 with travelling to the UK to carry out the nerve agent attack on Sergei Skripal.
Skripal, a former colonel in the GRU who was caught spying for the UK, and his daughter Yulia survived the assassination attempt.
The 69-year-old and Yulia, 37, were left fighting for their lives after they collapsed on a bench in Salisbury having been exposed to the nerve agent on their front door on Sunday March 4.
Immigration Minister Mr Foster said today: "People present themselves at Calais port pretending to be Ukrainian. I appreciate some opposite may think that’s not an issue.
"But we only need to look at some of the statements coming out of the Kremlin to see which countries are very much in the crosshairs of Mr Putin’s regime.
“And we only have to look back a short period ago to see the impact on this country of attacks by those pretending they’d come here to look at a cathedral spire."
But Tory MP Julian Sturdy said: “Now is not the time for box-ticking and red tape. Now is the time to do everything we can.No more excuses… Weeks is simply not good enough! These are women and children! We have to speed it up!”
And Shadow home secretary Yvette Cooper said: "Two million refugees have left Ukraine. Other countries are supporting hundreds and thousands of people. The Home Office is currently issuing just around 250 family scheme visas a day.
"Most want to stay close to home but some want to come here to join family or friends, and we should be helping them, instead most people are still being held up by our Home Office bureaucracy or being turned away."
A full family visa scheme for Ukrainians opened on Friday allowing applications from immediate family; extended family; and immediate family members of extended family.
Immediate family are a spouse or civil partner, unmarried partner in a cohabiting relationship for two or more years, a child under 18, a parent if their child in the UK is under 18, or a fiancee or proposed civil partner.
Extended family include grown-up children or their parents, grandparents, grandchildren or partners’ grandchildren, and brothers and sisters.
There will also be a sponsorship scheme for firms, charities and individuals to bring Ukrainians with no family links to the UK for 12 months, but it is not up and running yet.
Priti Patel had previously said it was important to have the centre "away from" Calais to avoid a "surge" of people to the English Channel port. Not all applicants will be able to use it - only Ukrainians referred to the centre by Border Force.
The visa centre in Lille is set to be set up within the next 24 hours and refugees could be offered transport to it from Calais, Mr Foster said.
He told MPs: “We are looking to establish a presence in Lille, and also potentially to look at transport options as well from Calais to Lille.”
He added: “We expect that to be set up within the next 24 hours.”
Mr Foster said the Home Office is training new case workers to make decisions from tomorrow, looking into technology previously used to bring people to the UK from Hong Kong, and reviewing some of the requirements for biometrics for under-18s to free up slots.
But he said: "Sadly we are already seeing people presenting at Calais with false documents, claiming to be Ukrainian.
"With incidents like Salisbury still in our minds, the government will not take chances with the security of this country and our people. Our friends in the US, Canada and Australia are rightly taking the same approach we are.”
He went on: “It is essential we do not create a choke point at places like Calais where there are dangerous people smugglers present, but also to ensure the smooth flow of people through the system from across Europe.”
But Labour MP Barry Sheerman said: “It’s not often I feel ashamed listening to a range of ministers with their half-baked excuses for no action.”
He added: “For God’s sake please… get your act together, and open your doors to these poor people.”