LONDON (Reuters) - Less than a month after losing one senior minister, Prime Minister David Cameron was forced to defend another on Wednesday as pressure grew on his interior minister Theresa May in a row over border security.
Cameron gave public backing to May as he sought to protect her from suffering the fate of former Defence Secretary Liam Fox who quit last month over his links to a friend who had falsely claimed to be his official adviser.
May's position weakened after the head of Britain's border force resigned on Tuesday and accused her of misleading parliament over an easing of passport controls at ports and airports that led to his suspension last week.
The borders row is damaging for Cameron's Conservatives, who came to power 18 months ago on a law and order agenda that included a pledge to reduce the number of immigrants coming to Britain.
The loss of another popular right-wing minister could add to turbulence for a coalition in which the centrist Liberal Democrats are the junior partner. Party critics have accused Cameron of pandering too much to his coalition partners and diluting the Conservative agenda.
Opposition Labour trained their fire on May after she revealed she had agreed a limited relaxation of border controls in a pilot programme from July to allow guards to concentrate on high risk travellers.
May said officials eased checks further without her approval, meaning that an unknown number of illegal immigrants, criminals and terrorists could have entered Britain as result.
"We cannot afford a Home Secretary (interior minister) who cannot cope with a crisis or sort out a fiasco," Labour home affairs spokeswoman Yvette Cooper told parliament.
Cameron, coming to May's aid, said her pilot programme, which included reduced checks on children in favour of targeting high-risk individuals, had not compromised security.
"This was an operational decision but one that I fully back and think she was right to take," he told parliament.
The government suspended UK Border Force chief Brodie Clark and two senior border force colleagues last week when the relaxation of checks was discovered.
Clark on Tuesday said statements made by May were incorrect and that by publicly declaring him to be at fault she had made his position untenable.
He said he had come under pressure from ministers to cut the size of queues of passengers waiting to pass immigration checks, an assertion May dismissed.
"I've never told officials to reduce queues at the expense of border security," May told parliament.
Reporting by Tim Castle; editing by Andrew Roche