The crown prince has made few public appearances in recent years

Walid al-Tabtabai told the BBC that replacing Sheikh Saad al-Abdullah al-Sabah would be the first step towards defusing the crisis.

The emir of Kuwait said on Tuesday that he would take "decisive action".

There has been concern over Kuwait's future leadership since June when Crown Prince Sheikh Saad al-Abdullah al-Sabah, 76, was admitted to hospital.

Sheikh Saad is set to succeed his 79-year-old cousin, Emir Sheikh Jaber al-Ahmad al-Sabah.

The Emir has seldom appeared in public since suffering a stroke in 2001.

Settling the issue

Mr Tabtabai, an Islamist member of parliament, told the BBC World Service that he did not have an opinion on who should take the place of the crown prince.

In a meeting with the assembly speaker on Tuesday, Emir Sheikh Jaber al-Ahmad al-Sabah expressed full confidence in Prime Minister Sheikh Sabah al-Sabah.

The emir said he was "settling the issues in the interest of Kuwait's security and stability" after Sheikh Salem al-Sabah, the head of the National Guard, called for a committee to be set up to "support the leadership" of the emir.