John Reid appeared to have won at least a stay of execution for his ministerial team over the criminal records fiasco last night although opposition MPs insisted that key documents at the centre of the row should be published.

Question marks remained over how much the ministers knew but there seemed to be general agreement that they had not been alerted to the scale of the backlog.

Senior MPs queried the robust denials from the Home Office when the blunder first hit the headlines on Tuesday night: they argued that ministers should not have taken to the airwaves without being totally aware of the fine print of all the correspondence.

Terry Davis, the secretary-general of the council of Europe, stepped into the argument yesterday to insist that Mr Reid, the Home Secretary, should not blame Europe for the criminal records backlog because the origins of the problem were in London.

The Home Office refused to publish the letters between the Association of Chief Police Officers (Acpo) and ministers, which relate to the controversy but opposition parties are determined to pursue the correspondence.

They lodged Freedom of Information Act applications for publication of the letters sent between Acpo and Tony McNulty and Joan Ryan, the two ministers most closely involved in the controversy, three months ago.

Mr Reid has insisted they will not be released while an internal inquiry - expected to take six weeks - is under way.

Nick Clegg, the Liberal Democrat home affairs spokesman, accused Mr Reid of "hiding behind the skirts" of junior minister Ms Ryan.

David Davis, the shadow home secretary, said: "It is long past time the public had straight answers and all correspondence was published."