An advertising blitz promoting the New South Wales Government's controversial greyhound racing ban has cost taxpayers nearly a million dollars.

A spokesman for Premier Mike Baird confirmed the million-dollar price tag to the ABC, as the Government prepares for a heated debate over the ban in Parliament this week.

The series of advertisements, which have been running across newspapers, radio and television, focus on animal cruelty and deaths in the greyhound industry and pose the question: "What's the real cost of greyhound racing?"

The Premier's spokesman has defended the price tag, saying it was less than 1 per cent of the Government's annual advertising budget.

"We make no apology for keeping the public informed of what is an important change, and telling affected communities and individuals where they can go for more information," the spokesman said.

But Opposition racing spokesman Michael Daley said the NSW Government had used the money to defend its "bad decision".

"Let's remember that the Government only started these advertisements four or five weeks after the decision was made, when they started attracting huge criticisms," he said.

"This is money that should have gone to schools and hospitals [but] the Government has spent it — taxpayers' money — on defending its own bad decision.

"If the Government was concerned about keeping the public informed, they wouldn't have rushed legislation through the Parliament to wipe the industry out."

Meanwhile, the bill to ban greyhound racing in New South Wales from July 1 next year is expected to pass Parliament this week, despite some Nationals MPs continuing to threaten to cross the floor to vote against it.

The bill was rushed through the Upper House earlier this month and will be debated in the Lower House on Tuesday afternoon, with a vote expected that night or the following day.

Labor has vowed to vote against the ban and has urged Nationals MPs, under pressure from their country constituents, to cross the floor.

A number of Nationals MPs, including Kevin Humphries and Katrina Hodgkinson, have indicated they cannot support the bill.

The Government announced it was moving to ban greyhound racing last month, after a Special Commission of Inquiry handed down an explosive report into animal cruelty and deaths in the industry.