THE Coalition's first major reshuffle has left David Cameron struggling to assert his authority after two ministers defied him and a row broke out over the UK Government's approach to aviation policy.

While the Conservative Right broadly welcomed the changes to Cabinet, the Prime Minister failed to force Iain Duncan Smith to move from his cherished Work and Pensions brief.

Baroness Warsi, who had publicly made clear she wanted to retain her Cabinet role as the Tories' co-chairman, was eventually persuaded to take a joint role as Foreign Office Minister and Faith and Communities Minister.

However, the largest shadow over Mr Cameron's shake-up came when a row erupted over the departure of Justine Greening from her role as Transport Secretary.

Ms Greening whose Putney constituency is under the Heathrow flightpath campaigned against a third runway at the airport – which is Coalition policy.

However, it seems clear the Conservatives and, most importantly, the Prime Minister are rethinking their view on airport expansion in south-east England.

Boris Johnson, the London Mayor, who wants a new airport built in the Thames estuary, accused Mr Cameron of plotting to abandon the Tories' manifesto commitment against a third runway.

Praising Ms Greening as a "first rate Transport Secretary", he said: "There can be only one reason to move her and that is to expand Heathrow Airport.

"Now it is clear that the Government wants to ditch its promises and send yet more planes over central London."

With the departure of Caroline Spelman and Cheryl Gillan from Cabinet and changes to Lady Warsi's role, the number of full-time women Cabinet ministers falls from five to four – Maria Miller and Theresa Villiers were promoted to the Culture and Northern Ireland briefs respectively.

Downing Street announced a series of moves at the minister of state level, the rank beneath Secretary of State in Whitehall departments, but all appeared to be men. Later, a string of junior ministerial jobs were announced, filled by the new intake of women MPs. Jo Swinson, the Liberal MP for East Dunbartonshire, becomes Consumer Affairs Minister in the Business Department.

No 10 insisted it was still the Prime Minister's intention to have one-third of his government made up of women by the end of the parliament.

However, Labour's Yvette Cooper said the reshuffle demonstrated the Prime Minister's failing attitude to women.

"David Cameron has always had a blind spot when it comes to women. Now he's done it again," she said.

While all the Liberal Democrat Cabinet ministers, including Danny Alexander and Michael Moore, stayed put, there was movement lower down the ranks.

As expected, Nick Clegg's favourite, David Laws, returned to government. He spent just 17 days at the Treasury in 2010 before an expenses scandal forced him out.

A LibDem source said it would be fair to say that making the Yeovil MP Education Minister would ensure the LibDems would know more about what was going on within the department.

Earlier this summer, the party was blindsided when leaked plans showed Secretary of State Michael Gove was planning to scrap GCSEs in England.

It was also stressed that Mr Laws would have a roving brief with a desk in the Cabinet Office, although he would not attend Cabinet.

With the departure of Nick Harvey from the Ministry of Defence, it will be Mr Laws who will take on the review of possible alternatives to the Trident nuclear deterrent.

However, the departure of Mr Harvey means there will be no LibDem at the MoD.

A senior party source made clear that not every department has had a LibDem minister in the past and that, in any case, all defence decisions have to go through the National Security Council, on which Mr Clegg sits.

Last night, opposition parties dismissed Mr Cameron's attempt to rejuvenate and refocus the Coalition.

Labour frontbencher Michael Dugher branded the Government shake-up a "no-change reshuffle".

He said: "No move for a failing Chancellor in charge of a failing economic plan that has delivered a double-dip recession, who gave a tax cut for millionaires and who refuses to tax bank bonuses.

"And there are no moves across almost all of the most senior Cabinet jobs."

He added: "This reshuffle isn't a fresh start – it's more of the same from an out of touch and failing Government that stands up for the wrong people."

Stewart Hosie, the SNP Chief Whip, said: "David Cameron's ministerial reshuffle will be pointless unless it is accompanied by an urgent rethink of the UK Government's failed economic strategy."

He added: "Westminster urgently needs to implement a policy of capital investment – as a whole range of economic commentators are calling for – and the Prime Minister and his Chancellor must act at last."

''