The government must give an immediate assurance that public funds won't be used for the National Party's planned Telstra sale advertising blitz, according to Independent Member for Calare Peter Andren.

"In fact the government has no right to use public funds for any advertising campaign, city or country, to try and explain away its totally unjustified decision to flog off the national telecommunications carrier," Mr Andren said.

"The very fact the Nationals need an ad blitz to try and justify their appalling sell-out underlines how unpopular the decision is among their claimed support base.

"Queensland Nationals' President and federal MP Bruce Scott says a campaign will be mounted and will possibly involve television, radio and newspaper advertising.

"This will cost several million dollars to have any sort of blanket coverage. Where is this money coming from? If it isn't public funding, and there's no way that could be justified, who is paying for it?

"I doubt the party would use up scarce election campaign funds, so it begs the question as to whether interests in the sale outside the party might be willing to help pay for such an advertising blitz.

"The advertising message will apparently be one that details how hard the party pushed to ensure protection of country services.

"That sort of spin will be met with anger and frustration by country Australians who believe the Nationals have seriously let down their constituents," Mr Andren said.

"A TV commercial or newspaper ad won't change the minds of the 90% of rural Australians and 70% across the broader electorate who have made clear they don't support a sale under any circumstances.

"The Nationals and the Liberals must come clean on just who will pay for this campaign. It is shaping up as a repeat of the outrageous use of taxpayers' money to pay for the politically motivated multi-million dollar Industrial Relations advertisements," he added.