Nepal's ruling Maoists warned yesterday that the Himalayan nation's peace process was "in peril" after the country's president attempted to stop them sacking the powerful army chief.

The ultra-leftists fired General Rookmangud Katawal for refusing to integrate former Maoist rebel soldiers into the regular army under the terms of a 2006 peace deal that ended a decade of civil war.

But President Ram Baran Yadav, a member of the main

opposition party, has told the head ol the army -- traditionally a bastion of Nepal's elite and the former monarchy -- to stay put.

Maoist spokesman and cabinet minister Krishna Bahadur Mahara told AFP this was tantamount to a "constitutional coup" and vowed to fight back with street protests.

'The president is... violating constitutional norms.The president's move has put the peace process in peril," he told AFP "Our party has taken die president's step as a constitutional coup and we will fight against it."

"The executive power to

sack and appoint an acting army chief lies with the government and not the president. We will stick to our decision," he said, adding the Maoist cabinet had instructed the president to back down.

The row is the worst crisis to hit impoverished Nepal since the peace deal was signed, and follows months of worsening tensions between the ex-rebels and their former foes in the military.

The Maoists want their fighters, currently confined to United Nations-supervised camps, to be given jobs in the regular army.