Liberal MP Bruce Billson's swan song

Bruce Billson may be best remembered for his passion for small business but it was veterans affairs which made the former federal minister tick.

Mr Billson, who is retiring after 20 years in federal politics, delivered his swan song to federal parliament on Thursday.

He was only told hours earlier it would have been his final opportunity to give the speech.

Mr Billson described his time as veterans affairs minister under the Howard government as "incredibly challenging".

One of the greatest moments was seeing the remains of Vietnam veterans return to Richmond air base in Sydney.

"What a moment," he told parliament.

Mr Billson, often referred to as the 'nicest guy in politics', admitted he was only ever thrown out once in his two decades in parliament.

Having entered the job in a marginal seat and working hard to keep it, he joked there should be a marginal seat hall of fame to honour those like him.

"Those in safe seats should pay appropriate homage at least weekly."

Mr Billson's political motto was "passion, positivity and an awful lot of persistence," - something he applied as small business minister under the Abbott government.

He loved every minute of it.

"Small business is the new black, everyone wants to wear it," he joked.