Lynne Featherstone is to replace Norman Baker as Liberal Democrat minister at the Home Office, Nick Clegg said today.

Ms Featherstone, who previously served as equalities minister, said she was "very happy to be returning to the Home Office".

Norman Baker has told how Theresa May and her closest aides repeatedly set out to shut down his activities at the Home Office as he defended his decision to quit as a minister.

The Home Secretary's special advisers scrutinised what he was up to then "tried to minimise my room for manoeuvre", he said.

However, seemingly contradicting Mr Baker's assessment, she said: "I have always had a very constructive relationship with Theresa May and I look forward to working with her again."

Conservative former minister Damian Green insisted that Mr Baker had been the cause of tensions in the department because he tried to act as if he had the same ministerial rank as Mrs May.

But the Lewes MP denied the claims and laid the blame for his departure firmly at Mrs May's door.

"I'm afraid that the Home Secretary, who I think is a formidable woman and a very competent Home Secretary, has one great drawback, which is that she regards this a Conservative department in a Conservative government and it's not," he said. "It's a Coalition department in a Coalition government and I'm afraid that mindset has rather soured things."

He added: "Clearly, there were issues which were in my portfolio which I wanted to take forward and under normal circumstances in any other department I would have been allowed to progress and really there were obstacles put in the way sometimes.

"Her special advisers, in particular, were scrutinising what I was doing and they tried to minimise my room for manoeuvre."

Mr Baker announced he was quitting last night, telling the Independent that working with Mrs May was like "walking through mud".

He highlighted a drugs report that Lib Dems claimed backed the case for a review of the current law, claiming it had been "blocked numerous times" by the Tories.

Mr Baker insisted today that he had formed good working relationships with "many Conservatives" in government, including Mr Green.

"Indeed, I've had a couple of texts this morning from senior Conservatives saying how sorry they are I'm standing down," he said.

But he refused to share the identities of the well-wishers, saying it "wouldn't help their career prospects".

Mr Baker said it had been "onerous" being the only Lib Dem at the Home Office and he was "not sure" that predecessor Jeremy Browne "did manage very well" in the department.

Asked if he was leaving a mess for colleagues to clean up, he replied: "No. I think what I'm doing actually strengthens the position because I think the Home Secretary, I hope, will now think more carefully about how she engages with her Coalition partners."

He added: "I think it is exceptional rather than symbolic as a matter of fact. I think relations across the Coalition are professional and by and large productive.

"I think the Home Office is the cutting edge of the Coalition in many ways. It's where the difficult issues arise - immigration and Europe and so on.

"It's not helped by the Home Secretary's views apparently that there is a Conservative Government with a few Lib Dems in it rather than a coalition Government."

Deputy Prime Minister Nick Clegg expressed regret at the loss of "one of the most effective ministers" in the Government but said he "fully" understood why he was stepping down.

"I understand and respect the reasons he has given for standing down as a minister. He was an outstanding minister, but these things happen," he said.

With Ms Featherstone moving to the Home Office, Baroness Northover will take her old job at International Development.

Lorely Burt and Tom Brake become Assistant Government Whips - the latter alongside his job as Deputy Leader of the House - after the departures of Mark Hunter and Jenny Willott.