The attorney general, one of the most europhile members of the government, has publicly attacked the European Commission as a ‘repeat offender’ in going beyond its legal powers.

His comments, in a speech in Brussels, will fuel the growing row over the commission’s plan to create a ‘European area of justice’, and the extent to which the UK can exercise the opt-out negotiated under the 2007 Lisbon treaty.

After taking pains to assert his pro-European credentials, Dominic Grieve said that over-stepping legal boundaries set by treaties ‘undermines the very legitimacy of EU action’. 

In particular, he said, the EU must not ignore the special arrangements for justice and home that pertain to ‘some member states’ under EU treaties. ‘It is unacceptable and very damaging to the legitimacy of the EU for legal bases to be aggressively exploited by the commission in order to side-step the opt-outs which have been negotiated by sovereign member states.’ 

One example of the commission over-stepping its authority was in its handling of plans to create a European public prosecutor.

Grieve said that 14 national parliamentary chambers had sent a reasoned opinion to the European Commission that the proposal breached the principle of subsidiarity. However the commission had gone ahead anyway.

‘To my mind, this can only strengthen the case for finding a way to give national parliaments a bigger and more significant role in the EU. I am afraid it also illustrates to me the extent to which some in the present commission now seem dangerously out of touch with the people of Europe they are supposed to serve.’

Grieve also described the commission as a ‘repeat offender’ in taking action without authorisation by governments through the Council of the EU. He cited the signing of a memorandum of understanding with Switzerland at a time when it was still under consideration by the council. ‘I have to say that I find this case very troubling both as a lawyer and as a government minister.’

Defending recent UK challenges to EU measures, he said: ‘The UK plays by the rules and we expect others to do so too.’

Comments by a member of the UK government may not cut much ice with the EU's justice commissioner, Viviane Reding, who recently singled out David Cameron for criticising 'bureaucrats in Brussels' for implementing measures which had been agreed by the British government.

However, Grieve's comments follow a call last month by Hubert Legal, counsel to the Council of the EU for more 'humility' and respect for national legal systems.