Saudi Arabia, the United Arab Emirates and Bahrain have withdrawn their ambassadors from neighbouring Qatar, as frustration over the gas-rich emirate’s maverick foreign policy prompts the worst intra-Gulf diplomatic crisis in recent history.

The three nations, which are seeking to marginalise their neighbour’s support for political Islam in the region, cited Qatar’s unwillingness to adhere to agreements of the 32-year-old six-member Gulf Co-operation Council as the reason for recalling their envoys, according to the official Saudi Press Agency.

Riyadh, Abu Dhabi and Manama also asked Doha, which has been a big backer of the Islamist Muslim Brotherhood group, not to “support any party aiming to threaten security and stability of any GCC member”.

They accused Qatar of failing to agree on a unified policy to “ensure non-interference, directly or indirectly, in the internal affairs of any member state” after it failed to sign up to a common security pact at a GCC foreign ministers meeting in Riyadh on Tuesday.

Qatar’s cabinet in a statement said that the ambassadors’ withdrawal had been driven by “a difference in positions on issues out of the GCC,” reiterating its commitment to the six-member group, adding that it would not reciprocate and withdraw its ambassadors.

The diplomatic crisis, a rare escalation of behind-the-scenes negotiation into a damaging public spat, poses the most severe challenge of the short reign of the young Qatari emir, Sheikh Tamim bin Hamad al-Thani. The sheikh met the rulers of Saudi Arabia and Kuwait in November, promising a new face to Qatar’s foreign policy.

“The new emir promised things would change, and he failed to deliver,” said Abdulkhaleq Abdullah, a UAE-based political scientist, referring to a meeting held between Sheikh Tamim and the Saudi and Kuwaiti rulers last November.

“There is a desire to sanction Qatar politically and diplomatically.”

Gulf states had believed the new emir would promote a more consensual approach to foreign policy, co-ordinating more closely with his GCC neighbours, rather than striking out on major policy initiatives alone.

”Qatar has been warned a number of times by GCC countries that its policies, particularly with regard to the Muslim Brotherhood, ran counter to the critical security interests of the region,” said Michael Stephens, researcher at the Royal United Services Institute in Qatar. “As a result the GCC nations have taken an unprecedented step to haul Qatar back into line, and further escalatory steps could be taken in future.”

Last month, the UAE rebuked the Qatari ambassador in Abu Dhabi after Sheikh Qaradawi, the spiritual leader of the Muslim Brotherhood who is based in Qatar, attacked the UAE for not supporting Islamic government.

The UAE’s crackdown on domestic Islamists has over the past couple of years prompted several disagreements, many of them on social media, between emiratis and Sheikh Qaradawi and his supporters.

Abu Dhabi this week convicted a Qatari national, dubbed a prisoner of conscience by Amnesty International, for aiding a banned UAE Islamist group that the authorities claim is linked to the brotherhood.

So far Qatar has not bowed to initial pressure from Abu Dhabi over Sheikh Qaradawi’s comments, says Andrew Hammond, a policy fellow at the European Council on Foreign Relations.

“Qatar does not want to allow Saudi and the UAE to dictate policy,” says Mr Hammond. “Qatar is convinced it is standing up for just causes, such as Egypt, as well as its interventions in Libya and Syria.”

The ousting of Egypt’s Mohamed Morsi, the country’s first elected president who was a member of the Muslim Brotherhood, has become the biggest flashpoint in GCC-Qatar relations.

The UAE, Saudi Arabia and Kuwait have generously supported the military-backed interim regime led by Field Marshall Abdel Fattah al-Sisi. Qatar, a financial supporter of Mr Morsi’s government, has criticised the manner in which the president was deposed.

The three Gulf states have also been pushing Doha to rein in its popular pan-Arab satellite channel, Al Jazeera, which they accuse of promoting an Islamist and Muslim Brotherhood agenda. Three Al Jazeera journalists are facing trial in Cairo on charges of belonging to the “terrorist” Muslim Brotherhood.

The channel’s reporting sparked another bilateral spat with Saudi Arabia, which recalled its ambassador from Doha between 2002 and 2007.

Oman, which does not tend to co-ordinate closely with the other Gulf monarchies, and Kuwait did not withdraw their ambassadors.