CAIRO — Egypt's House of Representatives voted on Monday to authorise President Abdel Fattah el-Sisi to provide military support to Saudi Arabia against attacks by the Houthis, clearing the two-thirds threshold the constitution requires before Egyptian forces can be sent abroad on a combat mission.

The decision gives Cairo legal cover to act in defence of the Gulf's largest economy as Houthi missiles and drones reach Saudi cities and oil installations. It does not order a deployment. El-Sisi has said Egyptian forces would move only if Riyadh asked, and no formal Saudi request has been announced.

Parliament authorised el-Sisi to take "the necessary measures to support the Kingdom of Saudi Arabia", according to Agence France-Presse. The National reported that the mandate covers the defence of Saudi "territory, sovereignty and holy sites against any external aggression" and requires coordination with Riyadh.

The chamber voted behind closed doors and has not published a tally. The Associated Press said the house, dominated by pro-government members, did not break the result down. Under Article 152 of the constitution, a combat mission abroad needs the support of two thirds of the 596-member house, or 398 members, The National reported.

Speaker Hisham Badawi chaired the session, which followed three rare secret meetings and two postponements, AFP reported. The vote had been set for the previous week and was put off after two days of deliberations.

El-Sisi has spent a week narrowing what the mandate would mean in practice. The support would "defend Saudi territory, and does not include an attack on Yemen", he said on Wednesday, according to AFP. "We are talking about defending the land and borders of the kingdom," he added, saying a diplomatic solution remained the priority.

The president was blunter in remarks last week reported by AP. "I'm not speaking about fighting anyone or attacking anyone. I'm speaking only for defense," he said. He said he had heard a great deal of talk suggesting Egypt was preparing to attack Yemen, and added: "That is certainly not the case."

A regional official, who was not named, told AP that Egypt would send air defence systems and aircraft to help shoot down missiles and drones aimed at Saudi Arabia, and that no ground troops would enter Yemen. Officials have not said publicly what form the support would take, or its size or duration.

The request came from el-Sisi himself. On 17 October, at a military academy graduation, he called it inconceivable that Saudi security should be harmed, The National reported. The following day the National Defence Council, which he chairs, pledged "all necessary and possible forms of support" to the kingdom and said Egypt would increase its diplomatic efforts.

Hussein Haridy, a former Egyptian assistant foreign minister, told Al Jazeera the decision "fully authorises the president" as commander in chief to help the kingdom defend its territory and infrastructure, and said the mission "is purely defensive in the sense it's not directed at any party in the region".

Four pro-government parties hold 403 of the 568 elected seats, and Assem El Gazzar, a deputy speaker and head of the National Front Party, said nearly 500 members had asked to speak, according to The National. The Wafd Party backed the request, calling Saudi security inseparable from Egypt's own. The Justice Party instructed its members to vote in favour, and the Nour Party called for defensive coordination with Riyadh.

The opposition Egyptian Social Democratic Party, which holds 11 seats, told its members to abstain. It said it had too little information on the mission's objectives, scope, duration and cost, and on the risk to Egyptian soldiers, and urged the government to put diplomacy first. Maha Abdel Nasser, one of its members, rejected the mandate as open-ended and vague, The National reported.

Medhat Rekaby al-Mansourawy, another member, told AFP the discussions were "surface-level without details" and said lawmakers had been assured the support would be "defensive".

Saudi Arabia is one of Egypt's largest financial backers, and the Houthi campaign is squeezing Cairo at the same time. A strike on Riyadh's international airport on 10 October killed 12 people, among them Azza Ramzy, a 28-year-old Egyptian flight attendant from Beheira province, according to The National. Houthi attacks have also hit Aramco facilities, disrupting flights and oil exports, Al Jazeera reported, and attacks near the Bab al-Mandeb Strait have reduced Suez Canal revenue.

Egypt joined the Saudi-led coalition in Yemen in 2015, sending naval vessels to the Red Sea off Yemen and no ground troops, AP reported. An older memory hangs over the debate. Gamal Abdel Nasser sent tens of thousands of troops into North Yemen in the 1960s, in an intervention the state newspaper Al-Ahram has called "one of the low points" of his presidency, AP said.

The Houthis have warned Cairo off. Yahya Al Raei, speaker of the group's parliament in Sanaa, wrote to Badawi that Egyptian involvement would pose "a grave danger" to Egypt's national security, The National reported.

Diplomacy is running alongside the mandate. Foreign Minister Badr Abdelatty travelled to Riyadh last Wednesday and said Cairo still favoured a negotiated settlement, Al Jazeera reported; he told AFP he was in daily contact with Iranian officials. UN Secretary-General Antonio Guterres, who met el-Sisi in Cairo on Monday, urged "maximum restraint" in a post on X and warned that further fighting could escalate beyond control.