Members of a secretive fund-raising body associated with Federal Treasurer Joe Hockey are being invited to pay $3000 each to be part of an exclusive budget day event attended by his most senior staff and key ministers.

The fund-raising body, the North Sydney Forum, offers exclusive access to Mr Hockey, often in private boardrooms, in return for political donations in the form of annual membership fees of up to $22,000.

But the forum and Mr Hockey refuse to disclose the names of its members. Mr Hockey has declined to say what meetings and discussions he has had with them because his diary is ''confidential''.Advertisement

The invitation to the May 13 budget day event – which features pre-budget briefings, lunch at Parliament House and dinner in the Great Hall – was sent in February by chairman of the North Sydney Forum John Hart, who is also chief executive of hospitality industry lobby group Restaurant and Catering Australia.

The industry group lodged a pre-budget submission calling for the removal of fringe benefits tax from ''business meals'' and an increase to the threshhold above which employers must pay superannuation to $600 a month.

Mr Hockey has refused to say what discussions he has had with Mr Hart or his association as part of forum activities about these or other issues.

In the invitiation, members and non-members (who may attend for a $4000 donation) are offered the chance to hear Small Business Minister Bruce Billson, Mr Hockey's chief economic adviser Tony Pearson and economist Ian Harper discuss ''Australia's economy now and into the future''.

Professor Harper was recently appointed by Mr Billson to head the government's review of competition policy.

After lunch Mr Hockey's chief of staff Grant Lovett and chancellor of the University of Western Sydney Peter Shergold will speak on ''government's role in the economy of the 20-teens''.

The invitation lists another speaker as ''Arthur Sinodinos – Assistant Treasurer''. But Senator Sinodinos' office confirmed he is not scheduled to attend after standing down from the position in March following his appearance at the Independent Commission Against Corruption.

Separately at ICAC on Tuesday, a barrister representing Senator Sinodinos argued against adjournment of the present inquiry, in which he is expected to be called as a witness.

The inquiry is examining claims the NSW Liberal Party – of which Senator Sinodinos is a former treasurer and president – disguised illegal donations through the party's main fund-raising body, the Millennium Forum, and a separate entity, the Free Enterprise Foundation, to bankroll its successful 2011 state election campaign.

The invitation to the North Sydney Forum budget day event directs donors to make cheques payable to ''Liberal Party of Australia (NSW Division)''.

Making out the payment to the party instead of the forum has the effect of preventing donors being identified as forum members on public disclosure documents.

As well, under federal laws, donations of less than $12,400 to a party in a year do not have to be declared to the Australian Electoral Commission.

Fairfax Media has previously revealed members of the forum include National Australia Bank and the Financial Services Council, which stand to benefit from proposed changes to the Future of Financial Advice Act that would weaken consumer protections.

Mr Hart did not respond to a request for comment.

Joe Hockey's Budget Day Party For Private Donors