The head of the UK Border Force has launched a scathing attack on Home Secretary Theresa May as he quit to launch a constructive dismissal case.
Brodie Clark denied "improperly" extending a relaxation of controls and accused Mrs May of making his position "untenable".
In a statement Mr Clark said: "I am anxious to take part in any independent inquiry into matters relating to UK Border Agency but my position at UKBA had been made untenable because of the statements made in the House of Commons by the Home Secretary Theresa May. Those statements are wrong and were made without the benefit of hearing my response to formal allegations."
He continued: "With the Home Secretary announcing and repeating her view that I am at fault, I cannot see how any process conducted by the Home Office or under its auspices, can be fair and balanced."
The move will heap pressure on Mrs May, who has already been forced to insist she will not resign over the issue. She is expected to face more questions from MPs after Labour called an Opposition Day debate.
Earlier, Mrs May told MPs she had rejected Mr Clark's proposed changes in favour of a more limited pilot scheme, designed in part to reduce queues at airports.
But Mr Clark went further, scrapping key checks against a Home Office database without ministerial approval, she said.
"Those wider changes were ones which I rejected," she said.
UKBA chief executive Rob Whiteman said in a statement later: "Brodie Clark admitted to me on November 2 that on a number of occasions this year he authorised his staff to go further than ministerial instruction.
"I therefore suspended him from his duties. In my opinion it was right for officials to have recommended the pilot so that we focus attention on higher risks to our border, but it is unacceptable that one of my senior officials went further than was approved."