Ministers have insisted the Government is committed to tackling inequality after the entire board of the Social Mobility Commission quit in protest at the lack of progress towards a “fairer Britain”.
Alan Milburn, the former Labour minister who heads the commission, said he had “little hope” the current Government was capable of making the changes necessary to deliver a more equal society.
He was joined in walking out by his three fellow commissioners, including the Conservative former cabinet minister Baroness Shephard.
The resignations are a major setback for Theresa May who entered No 10 promising to tackle the “burning injustices” that hold back poorer people.
Downing Street said the departures came after Mr Milburn – whose term as commission chairman expired last July – was told that a new chairman was to be appointed and that an open application process would be held for the role.
In his resignation letter, Mr Milburn said the preoccupation with Brexit meant the Government “does not have the necessary bandwidth to ensure the rhetoric of healing social division is matched with the reality”.
He added: “I have little hope of the current Government making the progress I believe is necessary to bring about a fairer Britain.
“It seems unable to commit to the future of the commission as an independent body or to give due priority to the social mobility challenge facing our nation.”
Appearing on BBC1’s The Andrew Marr Show, Mr Milburn said his reappointment for a second term was backed by Education Secretary Justine Greening but she had failed to prevail in Whitehall.
“I have decided I am not going to reapply for the job and frankly neither are the other three commissioners,” he told BBC1’s The Andrew Marr Show.
He added: “There is only so long you can that you can go on pushing water uphill.
“What is lacking here is meaningful political action to translate very good words into deeds. In the end what counts in politics is not what you talk about, it is what you do.
“What is needed is really clear leadership to translate perfectly good words into actions that will make a difference.”
Ms Greening refused to be drawn on whether she had fought for Mr Milburn’s reappointment.
“He has done a fantastic job but his term had come to an end. I think it was about getting some fresh blood into the commission,” she told The Andrew Marr Show.
Ms Greening denied that the Government lacked the will to tackle inequality, but admitted that more needed to be done.
“I think there is a real problem that we need to fix. Britain is not a country where we have equality of opportunity. Where you grow up affects your future far too much. This is a generational challenge.”
In her letter of resignation to Mrs May, Lady Shephard said she believed that “this moment of change” at the commission was the right time for her to leave.
“I have the utmost respect and admiration for what Alan has achieved in his committed work for the commission,” she said.
“I have much valued working with him, fellow commissioners and the highly dedicated staff. I believe that together we have been able to highlight policy areas of key importance to successive governments and to the future of our country.”