TEHRAN (Reuters) - Iran's highest legislative body said on Saturday it was ready to recount a tenth of the votes in a disputed presidential election and one reformist party said it was calling off a protest rally planned for later in the day.

Police warned they would deal firmly with any further street demonstrations over the June 12 vote.

Supreme Leader Ayatollah Ali Khamenei told protest leaders on Friday that they would be responsible for any bloodshed if rallies continued against the election, which he said was fairly won by hardline President Mahmoud Ahmadinejad.

The Etemad-e Melli party of one losing candidate, Mehdi Karoubi, said plans for a protest rally at 4 p.m. (1130 GMT) in downtown Tehran had been scrapped for lack of a permit.

"Because of not obtaining permission, the rally today has been cancelled," a party spokesman told Reuters.

Defeated candidate Mirhossein Mousavi, whose supporters have held huge unauthorised protests in Tehran and elsewhere in the past week, had demanded a complete annulment of the vote.

At their last rally in Tehran on Thursday, Mousavi supporters held banners saying they would gather again two days later. But an ally of Mousavi said the moderate politician had not urged people to demonstrate on Saturday or Sunday.

His supporters may show up anyway, as they did in their tens of thousands on Tuesday, even though Mousavi had told them to stay home. The protests have been the most widespread in Iran since the 1979 Islamic revolution.