Birmingham Post Political Editor Jonathan Walker watched Lin Homer endure an uncomfortable morning

MPs trying to work out just how Britain's immigration service turned into such a shambles weren't happy yesterday.

The Commons Home Affairs Committee had summoned Lin Homer, head of the Immigration and Nationality Directorate, to explain herself.

Ms Homer began well, offering to take the blame for the failings of her department. The buck stops here, and all that.

But immediately she claimed that "the full extent of the failure was only understood at a relatively junior level".

So it wasn't really her fault. The footsoldiers knew all about the problems, but never bothered to tell her.

Committee chairman John Denham demanded to know why the Home Secretary had inadvertently misled the committee last month - while Ms Homer sat next to him.

"I too was surprised," said Ms Homer. "It suggests we have a lot of work to do."

Mr Denham gave way to David Winnick, MP for Walsall North, who said it was "difficult to understand" how junior staff could be responsible for a series of blunders.

"What you didn't explain is what appears to be the total lack of management supervision . . . what on earth were the management doing?"

To put it another way, he wanted to know who was to blame. The Home Secretary, perhaps? Well, he's already been sacked, so no fun there. A permanent secretary maybe?

Or, hang on a second, here's a thought. Maybe we could blame you, Lin?

The report may decide whether Ms Homer keeps her job or not. On the plus side, it's hard to blame her for everything. On the negative side, she really didn't impress these MPs.