The actions of these delegates had led to bad publicity for teachers which cast a shadow over the public's perception of the entire profession, Mr de Gruchy told his own union's annual conference, in Llandudno.

BBC: Militants accused of harming teaching

The shadow chancellor argued that Mr Osborne was "conspiring in allowing the IMF to become the de facto central bank of the euro area" by agreeing to the deal at a recent meeting in Washington.

BBC: Osborne faces IMF funding backlash from MPs