The British government’s decision to grant temporary diplomatic immunity to the Egyptian president’s army chief of staff on a recent visit to London is to be challenged in the courts because critics say it thwarted efforts to arrest him over allegations of torture.

Lawyers acting for the Egyptian opposition Freedom and Justice party complained that the Foreign Office had issued a “special mission immunity” certificate to block “opportunities for arrest or interview” of Mahmoud Hegazy.

The solicitors say they got in touch with Scotland Yard’s war crimes unit when they learned that Hegazy was in Britain for a large arms fair in London, which began on 14 September. The police responded on 16 September saying: “We will consider any opportunities for arrest or interview [Hegazy] … as we have previously discussed.”

However, the police wrote back the next day saying Hegazy had been granted diplomatic immunity by the FCO and therefore could not be arrested. The lawyers for the Freedom and Justice party are now threatening to seek a judicial review of the decision to grant temporary diplomatic immunity to officials and aides.

The Egyptian president, Abdel Fatah al-Sisi, is due to visit Downing Street on Wednesday. The lawyers say the immunity order has set a precedent that could be used to protect “several suspects who will be travelling to the UK [with Sisi]. It is being challenged so that it is not relied on repeatedly in the same way to thwart applications for arrest warrants for alleged perpetrators”.

Senior officials from the Sisi regime have been accused of crimes against humanity after the massacre of more than 800 protesters outside Cairo’s Rabaa al-Adawiya mosque, the worst of three mass killings of supporters of the former president Mohamed Morsi during the summer of 2013. Sisi came to power after the army ousted Morsi in July that year.

In 2013 Hegazy was head of Egypt’s military intelligence and it is claimed he oversaw conditions in military detention centres and was “integral to the dispersal plans in Rabaa in August 2013”.

Last week, 55 leading figures from politics, journalism and civil society – including the shadow chancellor, John McDonnell – called for David Cameron to cancel an invitation to Sisi on the grounds that he is a military dictator responsible for a “regime of terror”. Special mission status is rarely sought by foreign nations on behalf of high-ranking officials as most visiting dignitaries are protected by diplomatic immunity under international law and have little to fear from domestic statute.

Last year the coalition government granted temporary diplomatic immunity to Tzipi Livni, Israel’s justice minister, to protect her against arrest and potential prosecution for alleged breaches of international law, including war crimes, over her alleged role in Israel’s 2008 military assault on Gaza.



When contacted about whether other Sisi officials had been afforded such protection, a FCO spokesman said: “In view of the confidentiality of diplomatic exchanges, we have no plans to make public further details about requests that have been granted or refused. Any application for special mission status is considered on its overall merits and may be accepted or refused on legal or policy grounds.”

Lord Macdonald, the former director of public prosecutions who is acting for Egypt’s Muslim Brotherhood as well as the FJP, said: “There is strong evidence [Sisi] is guilty of serious and very public crimes, including the mass shooting of demonstrators, forced disappearances, kidnappings, torture, the organisation of farcical trials involving mass sentences of death. We don’t think he is suitable company for the British prime minister.”

Tayab Ali, a partner with ITN solicitors, the firm representing Egypt’s now outlawed FJP, said the UK government’s actions had “frustrated the criminal process” and he would be seeking a judicial review of the decision.

“Cameron should be holding Sisi and his regime accountable for the many crimes they have committed and continue to commit in Egypt. The prime minister should be leading the call for these types of dictators to stand trial in international tribunals and not inviting them to tea in Downing Street. This double standard by our government fuels extremism while undermining justice and the rule of law.”

The Egyptian embassy in London has yet to comment.