Dominic Raab interviewed as part of bullying probe

Deputy Prime Minister and Justice Secretary Dominic Raab has been interviewed as part of an investigation into claims he bullied civil servants.

Senior lawyer Adam Tolley is leading an inquiry into eight formal complaints against Mr Raab and has already spoken to at least three senior civil servants from departments led by the minister.

Mr Raab, who is a close ally of Rishi Sunak, has denied the allegations.

But he has said he would resign if the inquiry concludes he has bullied staff.

The complaints relate to Mr Raab's time as justice secretary and foreign secretary under Boris Johnson, and his time as Brexit secretary under Theresa May.

The allegations began to emerge last year, and in November, Mr Raab asked for an investigation to be called.

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Mr Sunak has resisted calls from opposition parties and one senior Conservative, to suspend Mr Raab while his behaviour is investigated.

The prime minister has said he would wait for the outcome of the inquiry, before acting.

Speaking on the BBC's Sunday with Laura Kuenssberg programme, Mr Raab said: "I am confident I behaved professionally throughout​."

Asked whether there should be "more plain speaking in politics", he replied: "Yes, absolutely."

It was right for ministers to "challenge assumptions and test ideas" when working with civil servants, he added.

"I think for the lion's share of the time civil servants and ministers work very effectively together."

Appearing on the same programme, Dave Penman, head of the FDA union which represents civil servants said: "The picture he paints is that everything is fine in the civil service and the relationship between ministers and civil servants is OK.

"That's not the picture civil servants speak of, that's not their experience."

The BBC has been told that other civil servants who allegedly planned to file complaints did not after learning they would have been identified to Mr Raab as part of Mr Tolley's inquiry.