Labour pledges 'stronger' criminal checks on migrants
"Stronger checks" will be carried out to stop foreign criminals from becoming UK citizens if Labour wins the next election, Yvette Cooper has said.
The shadow home secretary told the BBC it was "shocking" that killers had been given British passports because "the Home Office failed to do basic checks".
The Home Office said it had inherited an immigration system "in disarray" and had introduced widespread reforms.
Chief borders inspector John Vine criticised existing checks, last week.
He said the Home Office had granted British citizenship to people with "very poor immigration histories" and he had been "concerned" to discover that applications for UK citizenship were not being scrutinised appropriately.
Ms Cooper told BBC One's Andrew Marr Show: "I think it's shocking that we have had people including serious criminals and killers [being] given British passports and British citizenship because the Home Office failed to do basic checks.
"I think we need much stronger checks in place, that must include a requirement on people applying for British citizenship to provide the equivalent of the Criminal Records Bureau checks from their own country."
Checks would be made on those without such a document to see if they have a criminal record in their own country.
She added that there would be more thorough border checks, aided by the proposed 1,000 additional border staff funded by visa waiver charges.
"We don't want those who have committed serious crimes abroad able to take advantage of British citizenship. We should have fair rules in place. Immigration is important to Britain but the system has got to be fair."
Conservative backbencher Peter Bone told the BBC that any future restrictions would only apply to people coming to the UK from outside the European Union.
"We're talking about people who're coming from non-EU countries where you can stop them and send them home and have controls, but, of course, if someone is coming from the European Union, and we're talking about hundreds of thousands each year, there are no controls. They're not allowed to have controls, the EU won't let you."
BBC political correspondent Alan Soady said immigration would be one of the big election issues and Labour was trying to convince voters that they can be trusted to tackle it. UKIP has accused the Conservatives of "total failure" to reach their target of cutting migration to less than 100,000.
Ms Cooper said immigration had been "too high" because of the level of low-skilled migration, which Labour would like to see lower - but she said they would not be promising a "no ifs, no buts" target, like the government's, which had been left in "tatters".
Student visitor visas, for short-term temporary students, and recruitment agencies that only recruited abroad and were undercutting local wages were areas that should be tackled.
A spokesman for the Home Office said migrants who break immigration laws will be banned from becoming British citizens for at least a decade and a decision to give Border Force its own separate command from 2012 had seen improvements in security.
He added: "The immigration system this government inherited was in total disarray, with visa routes open to widespread abuse, porous borders and a failing organisation administering it.
"We have reformed family, work and student visas to slash fraud and shut down 800 bogus colleges that were selling visas instead of education.
"And we scrapped UKBA, [UK Borders Agency} replacing it with a specialist border force, a visas unit and an enforcement arm to give all three crucial areas more focus and bring them under direct ministerial oversight.
"There is more to do, but our reforms are building an immigration system that is fair to British citizens and legitimate migrants and tough on those who flout the rules."
Meanwhile, an independent investigation into abuse at Yarl's Wood Immigration Removal Centre will be held by the next Labour government, the party says.
Two guards were dismissed in 2013 for inappropriate sexual conduct at the women's detention centre.
The 410-space immigration removal centre at Milton Ernest near Bedford is the UK's main removal centre, holding women and families who are facing deportation.