Individual high profile incidents should not derail "sensible discussion" on the role of special advisers in the civil service, Dr Tony Wright has said.

In an interview with ePolitix.com, the chairman of the Commons public administration committee said there was no evidence that Britain is moving towards an American-style politicised civil service.

Wright said there was a clear role for special advisers to play within the British system. He added that many civil servants would support the work of the political appointees as "a useful buffer between themselves and the political world of ministers".

But Wright said that it has been "dispiriting...that it has been almost impossible to have any sensible discussion about this issue in this country without people throwing up the charge of politicisation."

His comments follow high profile media rows over the work of Jo Moore, previously an adviser to Stephen Byers, and special advisers such as Alastair Campbell.

The committee chairman highlighted cases such as these as one of the reasons why "sensible" debate on the issue is difficult.

Wright said that "one or two incidents...distorted the whole debate".

"We just need to be absolutely clear about who does what and where someone's work stops and another persons work starts," he said.

"On any international test we are at one end of the spectrum in terms of the number of political people involved in government.

"I mean it is a perfectly proper thing to want to increase that somewhat, we just need to know what we are doing and what the boundary lines are."