TEHRAN (Reuters) – Iran will not back down “one iota” in its nuclear dispute with Western powers, President Mahmoud Ahmadinejad told a huge rally marking the anniversary of the 1979 Islamic revolution on Monday.

The West fears Tehran is covertly trying to obtain nuclear bombs. The Islamic Republic, the world’s fourth-largest oil exporter, says it needs nuclear technology to meet its booming electricity demand.

“They should know that the Iranian nation will not retreat one iota from its nuclear rights,” Ahmadinejad told the crowd which had gathered in the capital Tehran for the 29th anniversary of the revolution that toppled the U.S.-backed shah.

“They … cannot do anything except to play with papers and make propaganda,” Ahmadinejad said, referring to world powers discussing a third U.N. sanctions resolution against Tehran over work the West fears has military aims.

Iranian officials had called on people to turn out in large numbers to show their unity in the face of Western pressure. State television broadcast live footage of major rallies held in Tehran and other cities.

At Tehran’s Azadi square, Ahmadinejad asked the crowd: “Were you ready to retreat from your nuclear rights one step or one iota?” The demonstrators chanted: “No, nuclear energy is our obvious right.”

Coinciding with the anniversary, Iran displayed British boats which were seized in the Gulf, the semi-official Fars News Agency said, without making clear when they were captured.

“The boats of British violators seized in the Persian Gulf have been put on display in front of the Cultural Heritage Organisation,” Fars said without giving details.

In 2005, Iran put on display three British naval boats it seized the previous year, shrugging off protests by London which had demanded their return.

In March last year, Iran seized 15 British naval personnel along with their patrol boats in the northern Gulf. The British sailors were freed after a two-week standoff.