Prime Minister Tony Blair knew before the Iraq war began that it might cost him his job and would have resigned if a majority of lawmakers from his Labor Party had opposed his decision to join the fight, a newspaper quoted him as saying Friday.

In an interview with The Sun, the prime minister said he had told civil servants before that vote to prepare for the possibility that he might be forced to step down.

"It was always possible that you could be in that situation," the tabloid quoted him as saying. "In the end, if you lose your premiership, well, you lose it."

Blair faced intense opposition from many Britons — particularly Labor members — for his backing of the U.S.-led attack on Iraq, though recent polls show a majority now support his decision to send British troops.

He said his children had worried he might be ousted.

"I did sit down with them at one point and I explained that this was going to be extremely difficult and it was possible that the thing could go against me," he said.

The prime minister said he'd had trouble understanding the intensity of the opposition to his tough stance.

"I found it very frustrating and at times extraordinary that there were so many people against something that seemed to me in principle so obviously right," he said.

Blair acknowledged he'd been worried at times about the coalition's military progress.

"There were moments when it looked like we were getting bogged down and 10 days in you were worried about how long was this going to go," he said. "Had we miscalculated the degree of the depth of resistance?"

Blair said he was thrilled to see U.S. troops and Iraqis on television toppling a statue of Saddam Hussein in Baghdad.

"It was great," Blair said. "I was delighted and I was relieved.

Before the war started, 138 Labor lawmakers staged the biggest House of Commons revolt since the party came to power in 1997, voting for a measure declaring the government had not made a case for military action.

Still, a comfortable majority of Labor lawmakers backed Blair and supported the war.