No Gleeson advice on ex-senator Day

The solicitor-general was not asked to provide advice on the possible invalidity of Bob Day's election to the Senate, a senior minister says.

At a hearing of the legal affairs committee on October 14, Solicitor-General Justin Gleeson gave evidence that the day before he had been asked for urgent advice from the Australian Government Solicitor on a matter concerning "the composition of this Senate."

Mr Gleeson said the matter required action on behalf of the commonwealth "within a short number of hours or days".

However he declined to reveal any specific details of the advice.

Asked on Wednesday whether the advice related to Mr Day, Finance Minister Mathias Cormann told ABC radio: "No, it wasn't."

Shadow attorney-general Mark Dreyfus said the government needed to come clean on the advice, even if it did not relate to Mr Day - who tendered his resignation on Tuesday.

"Only a full and clear explanation will suffice at this time of great uncertainty," Mr Dreyfus said.

The Senate is expected to ask the High Court next week to consider whether Mr Day was validly elected on July 2 and may have breached the constitution.

The government has been investigating complex lease arrangements for Mr Day's electorate office in a building owned by a company linked to his former business partner.