Baroness Sally Morgan has made her displeasure about being ousted as Ofsted chair crystal clear in a strongly-worded attack on Michael Gove and his advisers.

Days after it emerged that the education secretary had decided not to renew the Labour supporter’s contract at the helm of the watchdog, Baroness Morgan has launched an outspoken assault on the government’s reform agenda - and the perceived hostility towards Ofsted emanating from the Department for Education.

In a move which will further escalate tensions between Mr Gove and Ofsted, Baroness Morgan warns of the dangers of creating an “unfettered, unregulated market in education”, which she claims would be a “disaster” for schools.

Reflecting on the pace of change in education at a meeting of the London Leadership Strategy in Westminster yesterday, Baroness Morgan asked: “Will we be momentarily seduced by all the current reform pyrotechnics but ultimately left deflated as success outside London remains patchy and our international competitors race ahead?”

She also blasted education commentators who have no experience of working in the sector.

“Many people outside education too are confident that the answer is simple and the solutions easy to implement,” she said. “If only teachers would listen to them; if only teachers taught and schools were run in the way these pundits prescribe.

“Not that these commentators have ever, by and large, been teachers. But then they think nothing of lecturing world-renowned geneticists about genes, so they are hardly likely to listen to teachers, however experienced, on the subject of education.”

This criticism appears to be a reference to Dominic Cummings, a controversial former special adviser to Mr Gove, who left his post at the end of last month. Mr Cummings claimed in a thesis leaked to the media last October that a child’s performance is influenced more by their genes than the quality of teaching they receive.

Baroness Morgan went on to stress the importance of “being mindful of our allies”, understood to be a reference to criticism of Ofsted.

Chief inspector Sir Michael Wilshaw has claimed he was “spitting blood” over criticism of his organisation from two right-leaning think-tanks with links to Mr Gove, one of which had asked if Ofsted was “fit for purpose”.

TES understands that rising tensions between the DfE and Ofsted stem from concerns within Mr Gove’s team over Ofsted’s criticism of some free schools. A second school - Al Madinah, in Derby - was told by the government today that it will have to close its secondary school after criticism from Ofsted, among others, that it is failing to provide a good enough quality of education.

Sir Michael is believed to have expressed concerns that the appointment of Theodore Agnew, a former party donor and academy sponsor, who has been strongly linked with the vacancy for Ofsted’s next chair, could undermine the organisation’s independence.

“I was never intimidated as a headteacher and I do not intend to be intimidated as a chief inspector,” he told the Sunday Times. Mr Gove was forced to issue a statement calling Sir Michael “a superb professional and an outstanding chief inspector” and denying that anyone working in the DfE had briefed against him.

In yesterday’s speech, Baroness Morgan argued that it was “not wise to blast away at one’s enemies if you routinely wound your friends”.

“That is a sure-fire way to win a battle only to lose a war,” she added. “We must work to bring people with us.

“In the campaign to improve our school system, there is no more steadfast ally than Ofsted under Sir Michael Wilshaw. I recognise that it is not necessarily fashionable at present to be a supporter of Ofsted. And I accept that it is never going to be universally popular. Inspectors rarely are.

“But Ofsted is the only impartial guarantor of England’s education we have. Any attempt to undermine it will ultimately damage the quality of our children’s education. Sir Michael and his team are doing a superb job. They deserve plaudits, not brickbats.”

Baroness Morgan also expressed concerns about the consequences of “increased diversity” in the schools sector, resulting from Mr Gove’s support for academies and free schools.

While acknowledging that current reforms are a “good thing”, she insisted that the “quid pro quo of increased diversity has to be impartial regulation”.

“Ofsted is that: an independent, impartial regulator, indifferent to political vagaries. Only it can protect the profession and the public from those who mistake enthusiasm for improvement, who confuse novelty with nous.

“An unfettered, unregulated market in education would be a disaster. It would inevitably allow malpractice to flourish, it would prove an easy target for those who never accept the need for change and it would set back the cause of educational reform for a generation.”