Infuriated by the move, Islah MPs - including Sheikh Abdullah al-Ahmar, who is parliamentary Speaker as well as the party’s leader - boycotted a vote of confidence in the new government.

Sheikh Abdullah sent a letter to parliament saying: "I refuse to preside over parliament sessions which will focus on discussing the government programme because it includes the abolition of religious institutes."

A statement by Islah said: "The government's decision is aimed at undermining an institution which is one of the greatest achievements of the revolution and of Yemeni unity. It is aimed at altering the Yemeni people's identity and destroying its religious and moral immunity."

In reality, the move has little to do with either religion or education but is almost certainly an attempt by the ruling General People’s Congress to further consolidate its hegemony over Yemeni politics.

The institutes - basically Qur’anic schools - developed in northern Yemen during the 1970s, mainly as a bulwark against the spread of Marxist ideas from the south. They were allocated a relatively generous budget and many existing schools converted into religious institutes with government approval.

Saudi Arabia, via the Islamic University in Medina, also supported the institutes - probably in the hope of steering northern Yemen away from Egyptian, Syrian and Iraqi influence.

By the 1990s, the institutes were widely regarded as a recruitment and propaganda vehicle for the Islah party. Selection of teachers remained outside government control and many arrived from Egypt, Sudan and Syria, employed more for their religious views than their teaching abilities.

In 1992, following the unification of north and south Yemen, parliament passed a law integrating the institutes into the state system. The government at the time was a coalition between the northern GPC and the formerly-Marxist Yemen Socialist Party which had ruled the south before unification.

Although the law never received presidential approval, under the constitution pertaining at the time, it became law automatically after 30 days.

It was not, however, implemented - mainly because the GPC saw the Islah party (which combines radical Islamic and conservative tribal elements) as a useful ally in its growing quarrel with the socialists.

In 1994 the quarrel developed into a full-scale war in which northern forces controlled by the GPC routed the socialist forces with help from Islah. Islah then became junior partner in a coalition with the GPC which ruled Yemen for the next three years.

The 1997 parliamentary election delivered a massive victory to the GPC. Islah won 53 seats out of 301 and, because of a boycott by the socialists, became the only significant non-government party in parliament.

Nevertheless, the GPC continued to expect a degree of co-operation from Islah and made clear that it could close the religious institutes if co-operation were not forthcoming. As a result, Yemenis often doubted that Islah was a true opposition party.

The question now is why the GPC has finally decided to carry out its long-wielded threat.

The most likely explanation is that it is connected with the violently-contested local elections last February, in which Islah presented a serious challenge to the GPC and accused it of cheating (MEI 645). Those elections, in retrospect, may be seen as the moment when Islah became a fully-fledged party of opposition.

Incorporating the institutes - there are thought to be about 400, with a total of 250,000 students - into the state system will undermine Islah activities at grass-roots level.

Other theories are that it may have a connection with the improvement in Yemeni-Saudi relations started a year ago by the border treaty, or that it could be a result of American pressure to clamp down on Islamist elements in the wake of the attack on USS Cole in Aden harbour last October.