Palestinian leader Mahmoud Abbas has told Hamas he is prepared to act if the incoming Hamas government damages the interests of the Palestinian people.
Mr Abbas is expected to approve the new Hamas-led cabinet
He warned prime minister-designate Ismail Haniya that he would "exercise his authority" if the need arose.
A Hamas spokesman said it was wrong to assume the party's policies would harm the Palestinians.
The Palestinian Legislative Council convenes on Monday for a confidence vote on the Hamas-dominated cabinet.
In a letter to Mr Haniya, Mr Abbas said "I will exercise my mandate and authority where and when they are needed to protect the higher interests of the Palestinian people."
Mr Abbas has previously called on Hamas to recognise Israel and respect previous commitments made by the Palestinian Authority, which Hamas has so far refused to do.
"Once your government assumes its responsibilities I ask you again to...make the necessary corrections to your programme," the Palestinian leader said in his letter.
Mr Haniya played down the prospect of a disagreement with Mr Abbas, according to the Reuters news agency.
"We do not seek to cause a constitutional crisis," he said.
Mr Haniya says his cabinet will be sworn in on Wednesday
Under current legislation, the Palestinian president is empowered by law to fire Mr Haniya if his policies are considered harmful to the national interest.
In January, Hamas won a landslide victory in the Palestinian parliamentary elections, winning 76 seats out of 132.
On Friday, Mr Abbas had suggested he could hold peace talks with Israel without the need for Hamas to be involved.
Israel has vowed not to deal with any Palestinian government that includes Hamas, and has called Mr Abbas irrelevant following Hamas' election victory.