ED MILIBAND'S ­relationship with the trade unions has become toxic, Michael Gove, the UK Government's Education Secretary, will say today in a personal attack on the Labour leader.

Mr Gove will also brand him uncertain, irresolute and weak.

In a sign Tory high command is intent on intensifying its attack directly on the Labour leader, Mr Gove will say Mr Miliband does not have the legitimacy of having had the majority support of the party's MPs or its members; he won thanks to the trade unions.

In his speech, he will say: "That is the key to his weakness. He was put in place by organisations with an agenda as they believed he would be the most pliant personality available.

"The reason why the trade unions have become a toxic issue for Ed Miliband is his failure to appreciate that ... radical left-wing union leaders now believe the Labour Party can be theirs again and they are taking it back - seat by seat, policy by policy - before his impotent gaze."

The Secretary of State will say the attempt by union bosses like Unite's Len McCluskey to take control of Labour had been blatant long before the row earlier this year over the candidate selection in Falkirk.

He pointed to Unite's ­political strategy document, which in 2011 had a shopping list of an end to spending cuts, an end to welfare reform and more legal freedoms to "disrupt people's lives with strikes".

He will also claim: "Unite is open that it has adopted the classic tactics of entryist organisations throughout the ages. It would get its people to enter moribund local party organisations, take them over and then select candidates, who were either members of their organisation or fellow travellers. Through the accumulation of muscle on the ground, power would be won at the top

"At the heart of the ­strategy - as events in Falkirk revealed - was the use of those union resources to ensure every safe or winnable Labour seat, which came up, was won by Unite or its people."

"To the question - who governs Labour? - his answer would appear to be, increasingly, the unions."