Secretary of State Theresa Villiers has denied she was moved to Northern Ireland because of the catastrophe over rail franchises.
The former Transport Minister blamed “regrettable and unacceptable” errors by civil servants, saying she had asked questions about the tendering process and been told everything was on track.
Three officials have been suspended after the award of the West Coast Mainline to Firstgroup was scrapped because of flaws in the bidding process — costing taxpayers an incredible £40m.
Labour has pointed the finger at Ms Villiers and former Transport Secretary Justine Greening, suggesting David Cameron foresaw the crisis when he moved both ministers out of the Department for Transport last month.
Ms Villiers said: “That’s just not true, because these problems didn’t come to light until after the reshuffle had taken place.”
Speaking for the first time about the franchise since the debacle emerged, Ms Villiers said: “As soon as the officials drew to the attention of Justine and myself that there was a potential problem she ordered this investigation to take place. That ultimately led to uncovering these very serious mistakes. I challenged the process, at all times I was told that it was a sound and a robust one. This investigation has turned up these really regrettable and unacceptable errors by the civil servants.”
The tendering process is deliberately designed to limit the involvement of politicians, she said.
Speaking to the Belfast Telegraph at the Conservative Party conference in Birmingham, Ms Villiers also revealed she is against any tightening of the abortion laws in England and Wales.
At the weekend, Health Secretary Jeremy Hunt said he would like to see the current 24-week limit lowered to 12. Abortion is deemed a matter of conscience, and MPs are given a free vote, not bound by party lines.
Ms Villiers, who has previously backed no change to the limit, said: “I don’t see the need for a change in the current laws, but again that’s my personal view.”
The Government has no plans to change the law, she said, and added that it would be “really inappropriate” for her to get involved in the row over whether abortion should be legal in Northern Ireland.
Tory supporters yesterday debated Government plans for gay marriage, which were opposed by Ms Villiers’ predecessor, Owen Paterson.
She said: “I voted for civil partnerships, and yes, I can see a case for equal civil marriage.
“But I think it will be important for the Government to look carefully at the responses to that consultation before they decide what to do and I’m sure that’s going to be the case.”
She also defended the Government's welfare reform programme, after Chancellor George Osborne announced a further £10bn of cuts to benefits.
Ms Villiers said she was “well aware” of concerns about a disproportionate impact in Northern Ireland, insisting ministers would listen to concerns.
And she insisted she had been “pretty visible” in the first few weeks in her new job, adding: “I also do think that it’s wise to learn as much as possible as quickly as possible before starting to express opinions on things like that.”
On the rail crisis: “As soon as the officials drew to the attention of Justine Greening and myself that there was a potential problem she ordered this investigation to take place.”
On the current abortion laws: “I don’t see the need for a change in the current laws, but again that’s my personal view.”
On civil partnerships: “I voted for civil partnerships, and yes, I can see a case for equal civil marriage.”