Shadow defence secretary Jim Murphy has written to David Cameron to demand he answer a series of questions about Liam Fox's conduct, in a fresh sign that Labour are unwilling to let the scandal die.
Fox resigned as defence secretary following a barrage of allegations about his working relationship with his close friend Adam Werrity.
He quit before the publication of a highly critical report into his behaviour by Britain's top civil servant, Sir Gus O'Donnell.
But Murphy says questions remain about Fox's conduct, including whether the practice of circumventing the civil service with unofficial advisers is more widespread in government.
Among Jim Murphy's demands is that Downing Street publish a full list of people who gave money to Pargav Ltd, the organisation that funded Werrity's jet-setting lifestyle.
He also wants Downing Street to publish a full list of ministers, MPs and government officials who met Werritty. Since Fox's resignation it has emerged that Werritty also met defence ministers Gerald Howarth and Lord Astor without civil servants present.
Labour is also digging around to see whether other ministers have engaged in similar activity. Murphy wants to see a a full list of official visits and meetings overseas involving ministers where a government official was not present.
In his letter to the prime minister Murphy writes: "The cabinet secretary's report into the conduct of the Rt. Hon. Member for North Somerset detailed precisely how his behaviour constituted 'a clear breach of the Ministerial Code'.
"The report, however, was limited in scope and does not confront all of the issues which led to the resignation of the former defence secretary and which go to the heart of trust in the government and the country's political system. Indeed, revelations continue to emerge which require explanation.
"It is essential that the outstanding and unresolved issues are addressed so that the full truth of this matter can be established. People will have found your dismissal of direct questions during prime minister's questions completely at odds with the transparency of which you have regularly spoken.
"We still do not know the full facts about the money trail which led to the resignation of the Rt. Hon. Member for North Somerset, we do not know the true role and motivations of Mr Werritty, and we do not know who exactly in the Government met Mr Werritty and whether there was any prior knowledge of the former defence secretary's activities.
"I enclose 10 questions which have not been answered by you, the Leader of the House or the Cabinet Secretary's inquiry. Only once we reveal the full extent of the wrongdoing which took place at the heart of government will we be able to ensure this can never happen again.
"As you have said in the foreword to the Ministerial Code, 'people have lost faith in politics and politicians. It is our duty to restore their trust. It is not enough simply to make a difference. We must be different.' It is your responsibility to give these words meaning by publicly providing answers to these questions.
"Throughout this scandal it has been clear that you have tried to avoid public association with it. It is not credible to continue to refuse to answer the questions about the actions of the individual you chose as your first defence secretary at such a crucial time for our country."
Fox is facing a fresh inquiry by the parliamentary standards commissioner, John Lyon, after Labour MP Nick Smith accused him or breaching the Political Parties, Elections and Referendums Act by failing to declare donations he received.
He is already under investigation by Lyon following accusations he abused his parliamentary expenses by letting Werritty stay rent free in his taxpayer funded flat.
The 10 questions Murphy wants answered by the prime minister are:
1. Can you give a categorical guarantee that over the past 18 months no other Minister has been engaging in similar activities to those which led to the Rt. Hon. Member for North Somerset’s resignation?
2. Will you provide a full list of organisations that have made donations, directly or in kind, to Pargav Ltd, and in particular will you provide the details of which IRG Ltd the Cabinet Secretary’s report makes reference to?
3. How many donations did the Rt. Hon. Member for North Somerset solicit for organisations in which Adam Werritty is involved, how much were these donations worth and for what purpose were they solicited?
4. Will you publish a full list of the concerns that were raised within government about the activities of Rt. Hon. Member for North Somerset and Mr Werritty, including details of by whom the complaints were made and when.
5. Will you now, as a matter of priority, publish the full list of ministers, MPs and staff within government who met Mr Werritty, as you said you would consider at Prime Ministers Questions last week, and as the Leader of the House said you would yesterday?
6. Were you aware that a Conservative Party Treasurer, Howard Leigh, introduced Liam Fox to donors who funded Adam Werritty?
7. What issues were discussed between Gerald Howarth MP, Minister for Defence Exports, and Lord Astor, Lords Spokesman on Defence, and Adam Werritty during their meetings, and were civil servants present?
8. Can you provide a full list of meetings between ministers and external organisations which have raised substantive issues relating to departmental decisions or contracts where an official was not present?
9. Can you provide a full list of official visits and meetings overseas involving Ministers where an official was not present?
10. Sir Gus O'Donnell recommended that "Permanent Secretaries should discuss with Ministers at the time of their appointment and regularly thereafter whether any acquaintances or advisers have contractual relationships with the department or are involved in policy development”. In the interests of transparency, will you publish details of all such relevant acquaintances and advisers?