Deputy Premier Andrew Stoner has retained a pay rise despite a concerted attack by Labor MPs, who accused the "greediest man in parliament" of double dipping while capping the pay of public sector workers.

Labor MP Walt Secord introduced a disallowance motion to the Legislative Council on Wednesday to block the $1000-a-week pay rise Mr Stoner will get when Premier Barry O'Farrell is away.

He rejected claims Mr Stoner deserved payment for carrying out additional duties, saying that was already recognised by his salary, the second highest in parliament.

"Until now a deputy premier has received no extra payment while filling in for the premier," he told the upper house.

"It is insulting and arrogant when the O'Farrell government is slashing 15,000 workers, cutting $1.7 billion from local schools and ripping $3 billion from hospital budgets."

Details of the payment were revealed on Friday with the publishing of a regulation from Mr O'Farrell granting the pay rise.

Mr Secord questioned why the issue hadn't gone before the Parliamentary Remuneration Tribunal, saying it had been done in secrecy with "a nod and a wink".

Labor MP Steve Whan said the government had failed to follow proper process and accused it of giving "a favour to a deputy" while imposing a 2.5 per cent cap on the wages of teachers, nurses, firefighters and paramedics.

Greens MP John Kaye said the allowance amounted to double-dipping, adding the pay increase sent "an appalling message to the people of NSW".

"He is getting paid twice for the one acting function," Mr Kaye added.

Roads Minister Duncan Gay was the only member of the government to speak against the motion, which was defeated 20 votes to 17, telling upper house MPs Mr O'Farrell only took off four weeks a year.

"(Mr Stoner) will receive on average an additional $4000-a-year," said.

The matter was later raised in question time, when Mr Stoner said a higher duties allowance was standard and "brings NSW further into line with the commonwealth".

He said the principal was "further enshrined" in public sector awards.

However, Mr Secord said it was "a naked cash grab" and pointed to reports in Wednesday's media that Mr Stoner had added $169,000 in travel claims to his $290,000 annual salary.

"The deputy premier is without a doubt the greediest person in this building," he said.

In question time on Tuesday, Mr Stoner defended the pay rise, saying it was standard practice in the federal government and across Australia.

"It brings NSW into line with the commonwealth and recognises the additional responsibilities involved when acting as premier," Mr Stoner said.

"In fact, I didn't hear word one out of those opposite when the same arrangements applied for (deputy prime minister) Wayne Swan."

He said receiving higher pay for performing extra duties was "in every award in (NSW)".