European Union leaders have dropped plans to discuss an ambitious reform of the bloc's institutions at a summit tomorrow and Friday because of looming war in Iraq, a spokesman said yesterday.

The 15 leaders had been due to receive a briefing from Valery Giscard d'Estaing, head of a Convention drafting a first constitution for the EU, and to discuss the future of the bloc's institutions, the most contentious issue facing the forum.

"The president perfectly understands that at a time when military action is probable, the European Council is not in a position to talk about institutional questions," Nikolaus Meyer-Landrut, spokesman for the Convention, told Reuters.

However, the summit will go ahead in Brussels, slightly shortened, with the Iraq crisis and economic reform as the remaining agenda items.

The Convention is due to present a draft constitution to EU leaders at a summit in Thessaloniki, Greece, on June 20-21 but the Iraq crisis, which has deeply split the EU, has cast doubt on whether the work can be concluded on time.

The 105-member forum has yet to address the core issues of who will wield power in a future EU of 25 or more members, and how a common foreign and defence policy will be conducted.

Giscard said on Monday he intended to discuss possibly extending the Convention's mandate until the end of September. Meyer-Landrut said Giscard was available to discuss the core issues when it suited the presidency to reschedule the meeting.