Philip Mawer, the newly appointed parliamentary commissioner for standards, has warned that he will not allow MPs to frustrate his investigations.

In an interview broadcast on Sunday, the new watchdog said he would be forced to "consider his position" if he did not get the support he expected from MPs.

"Obviously I want to work closely with the select committee and I would hope and expect that there would not be the sort of difficulties which had been alleged," he said.

"If there were, I would first take my concerns to the speaker and the Commons in general and then, obviously, if I was not satisfied, I would have to consider my position."

The new commissioner told Breakfast with Frost that he would be "nobody's patsy" and would stand firm in the pursuit of wrongdoing.

His claims followed revelations made by Elizabeth Filkin, the former commissioner, who alleged that MPs on the cross-party standards and privileges committee had "watered down" her reports.

Filkin also accused MPs and ministers of conducting a "whispering campaign" in an effort to discredit her.