Economist David McWilliams asked for a €100,000 payment to manage the recent economic think-in at Farmleigh, but was refused by the Department of Foreign Affairs.

McWilliams has been credited with coming up with the idea of the Global Irish Economic Forum, which took place in September, and it emerged last week that he was paid €10,000 for his role in the event.

However, the Sunday Tribune has learned that, in correspondence with the Department of Foreign Affairs earlier this year, he was seeking a multiple of that figure in return for organising the entire event.

The department politely but emphatically declined the offer, insisting that it would fund and organise the event, taking advantage of its embassy network and the IDA's global contacts to promote the forum and attract participants.

This happened in April when the Taoiseach sent out a personal message to top entrepreneurs and business leaders with Irish roots asking them to attend the conference.

McWilliams, whose book Follow the Money was launched last week, did have a role in the think-in, acting as moderator for two discussions. He was paid €4,000 for this and a further €6,000 for "consultancy and promotional activities".

McWilliams, who also presents RTE's Addicted to Money and The Panel, could not be contacted this weekend. But last week he defended the payments, stating that waiving the fee would be like "asking a plumber to fix your drains for nothing". While other participants did not receive money for transport costs or attendance, McWilliams said in a newspaper interview that the people who "didn't receive any payments were representing very large international companies. I was representing myself."

The Farmleigh event cost €309,515, including a cultural trip to Croke Park – allowing 94 delegates watch the All-Ireland football final – costing €13,000 for the event.

McWilliams was at the centre of controversy last week for revealing details of a private meeting with finance minister Brian Lenihan and for comments about RTE Prime Time presenter Miriam O'Callaghan in his new book.