Getup director Simon Sheikh has collapsed on the ABC's Q&A program having suffered an apparent seizure.

Mr Sheikh slumped forward as panellists discussed the carbon tax on Monday night, with his head making an audible thud on the desk.

Climate Change Minister Greg Combet and members of the show's crew rushed towards Mr Sheikh.

He regained a degree of consciousness and said "sorry, I just fainted", before he was helped backstage.

Q&A host Tony Jones said a few minutes later that Mr Sheikh had suffered a seizure and had been taken for a checkup.

Mr Sheikh's wife, Anna Rose tweeted soon after: "Thanks everyone for your concern for Simon. Ambulance has just arrived".

Twitter users had earlier suggested that Mr Sheikh struggled with a couple of his answers earlier in the program.

*[UPDATE]*
Mr Sheikh later took to Twitter from hospital.

"For those watching Q&A sorry I couldn't stay - I'm in hospital, thanks for all your support".

Twitter users had earlier suggested that Mr Sheikh struggled with a couple of his answers earlier in the program.

GetUp describes itself as a grass-roots community advocacy group.

GetUp! released a statement later saying Mr Sheikh had been given the all-clear by doctors at Liverpool Hospital in Sydney, where he was taken after the collapse.

Mr Sheikh has been battling the flu for a number of weeks, the statement said.

“We have a number of important campaigns we are working hard on at GetUp right now and perhaps like a lot of us, I have been burning the candle at both ends,” Mr Sheikh said.

Mr Sheikh said he was grateful for the messages of support he has received and was keen to let everyone know he was recovering.

“I am sorry to have caused any concern and am grateful people have been texting and emailing to check everything is okay,” he said.