(CNN) Egypt's Parliament has approved constitutional changes that will allow President Abdel Fattah el-Sisi to tighten his grip on government and stay in power until 2030, as authorities block a growing online petition against the changes.

The 596-member Parliament, which is dominated by Sisi supporters, only needed a two-thirds majority to pass 14 amendments and several new articles on Tuesday.

The changes to the 2014 constitution are expected to be put to a public referendum next week before taking effect, according to state-run Ahram online, citing Parliament Speaker Ali Abdelal. The official announcement will be made by the National Election Authority.

The constitutional amendments will extend a presidential term from four to six years. They would add two years to Sisi's current term and allow him to seek re-election in 2024.

"I have repeatedly said ... that the President did not intervene in the amendments and did not request them," said Abdelal.

The changes will give the military more power by stipulating its responsibility "to preserve the constitution and democracy, maintain the basic pillars of the state and its civilian nature."

They also expand Sisi's power over the legislative branch by creating an upper house known as a senate, a third of whose members will be appointed by the president. The size of the lower house will be reduced, with at least 25% of them reserved for women.

The revised charter also gives the president new authority to appoint members of the judiciary.

Sisi, a former general, became president in 2014 after a coup the previous year. He was re-elected in 2018 with 97% of the vote

Steps toward authoritarianism

Supporters of the changes said they would bolster Egypt's economy, which is struggling to recover from the political turmoil of recent years, and strengthen security.

"The amendments serve the national interests of Egypt, helping to reinforce stability and widen the scope of participation in political and parliamentary life," said Kamal Ahmed, a pro-Sisi member of Parliament told Ahram newspaper.

Opponents see a further step toward authoritarianism.

The government has recently intensified its crackdown on opposition to the amendments, with an online petition blocked by internet providers at least three times since its launch on April 9, according to external internet monitors.

Even so, it has so far attracted more than 277,000 signatures, according to internet monitor NetBlocks.

The website can still be accessed from abroad, via Facebook links and through the use of a virtual private network (VPN).

The organizers of the Batel petition ("void" in Arabic) say it aims to rally support against any attempt to extend Sisi's rule and to subjugate the courts to his rule.

Egypt's judiciary is "the last standing tenet of democracy," Mohamed Sultan, a human rights activist and founder of Freedom Initiative, told CNN . "Sisi is expanding his powers within the judiciary in a way that is unprecedented -- not even under (Hosni) Mubarak's 30-year reign over Egypt."

Critics say President Donald Trump's warm welcome of Sisi to the White House recently has emboldened him.

"President Trump bears some responsibility for what's happening in Egypt in regards to human rights and Sisi's elimination of all opponents," said Mohamed Ismail, a member of a group called Egyptians Abroad for Democracy Worldwide.