The Liberal senator said he was pleased to be hosting drinks for the religious lobbying group and denied it was a fundraiser.

Mr Shelton said he was approached by Mr Canavan several months ago with the drinks set to take place Tuesday, June 20.

"[Senator Canavan] rang me some months ago ... and just wanted to do something to help encourage our team after what was a pretty traumatic event," Mr Shelton said.

The ACL's headquarters in Deakin were damaged when a van exploded outside in December last year.

"It has been a tough year for the ACL staff," Senator Seselja said.

"As a member of parliament I host many events for various community and religious groups and this is yet another event that is being held for all members, senators and staff."

"In the lead up to last year's federal election, both Liberal and Labor candidates attended an ACL forum to discuss important issues; the only party to boycott this was the Greens."

Mr Shelton said similar events were held in the parliament regularly.

Mr Shelton has previously compared the push for gay marriage and the Safe-Schools program to the Holocaust, writing they all happened due to a lack of strong moral guardians.

A man has been charged over the car explosion outside the ACL's offices.

The 36-year-old Deakin man suffered serious burns in the incident and was flown to Sydney for treatment a day after walking five kilometres to Canberra Hospital in the wake of the late night explosion.

Tenants, including the ACL, had to vacate the building after the explosion involving four nine-kilogram gas cylinders in a van.

But there was a delay in investigating due to the man's ongoing treatment for serious burns and a mental health condition.