Labour chairman Charles Clarke has been appointed education secretary in Tony Blair's cabinet reshuffle.

Mr Clarke - who BBC political editor Andrew Marr described as the "ultimate toughie" - replaces Estelle Morris who dramatically stepped down on Wednesday.

Cabinet changes

Education Secretary: Charles Clarke Labour chairman: Dr John Reid Northern Ireland Secretary: Paul Murphy Welsh Secretary: Peter Hain

Ms Morris quit after admitting that she felt she had not done well enough in the job.

Northern Ireland Secretary Dr John Reid is to replace Mr Clarke as party chairman.

The BBC's political editor Andrew Marr speculated Dr Reid had been given the job because he was tough but also a "conciliator".

He added that Labour was gearing up for some tough battles with unions - and possibly with Labour MPs over Iraq.

Dr Reid told BBC2's Newsnight on Thursday one of the big challenges he and his party faced was over public sector pay demands.

"If you want to really deliver quality services, it is no good just putting in investment unless that's accompanied by reform of the delivery system," he said.

'Confident'

"If the money we put in which is massive is all used on pay increases then obviously it doesn't feed through to better delivery."

Welsh Secretary and former Northern Ireland Minister Paul Murphy steps into the role of Northern Ireland secretary.

Peter Hain, currently Europe minister, moves to the Welsh office as secretary of state.

The cabinet has a new look

Mr Hain will retain his position on the Laeken Convention on the Future of Europe, the body set up last year to chart the future of the EU.

But an announcement as to who will replace him at the Foreign Office is not expected until Monday.

Mr Clarke, a former junior education minister, said his new role was "a fantastic challenge" and he was "really looking forward" to doing all he could to improve education in the UK.

He also praised the "commitment and integrity" of his predecessor.

Mr Blair said he wanted Mr Clarke to carry on the reform programme started under Ms Morris.

The prime minister also praised Ms Morris as an "extremely honest person" who cared deeply about education, and said she had quit her job with the "dignity and integrity that was her hallmark in office".

'More choice'

Conservative leader Iain Duncan Smith said the resignation of one person would not save the "crisis" in education.

Jerry Bartlett, assistant general secretary of teaching union NASUWT, said Mr Clarke's "legendary blunt speaking did cause us some problems" when he was a junior education minister under David Blunkett.

I'm not having second best in a job as important as this

Estelle Morris

He said Mr Clarke had indulged in "ill-informed criticism of teachers' trade unions", but on balance teachers' leaders had found him to be "quite constructive".

Mr Bartlett said Ms Morris' resignation was a "matter of some regret" among teachers.

Ms Morris resigned after coming under sustained media pressure over the A-level marking debacle, missed education targets and her intervention in an expulsion row.

In a letter to Ms Morris, the prime minister said he was certain she would return to government.