The best birthday present for jailed former opposition leader Anwar Ibrahim would be a united opposition against BN to face the 14th general election.

In recalling the opposition's victories under Anwar's leadership, National Human Rights Society (Hakam) chairperson Ambiga Sreenivasan said there has only been progress since the 1998 Reformasi movement that was triggered by his sacking as deputy prime minister by then prime minister Dr Mahathir Mohamad.

"Only Anwar Ibrahim could create an opposition front so strong that in 2013 they won the popular vote.

"We must never forget that," Ambiga said in her speech at a gathering held outside the Sungai Buloh Prison last night to mark Anwar's 69th birthday.

Even to this day and from behind the bars, Anwar's struggles for Malaysians have not ceased, Ambiga reminded the crowd of about 500 people.

"It must always be about the people and that is what we must continue fighting for.

"It is a crime to put a man away like that… But his spirit is not broken. He still looks strong and his message has never changed," said Ambiga (photo), who described the Reformasi era as a turning point for Malaysia.

"So today, when we celebrate his birthday, we also celebrate the man who shows fortitude and courage.

"I ask all of you today, let us make a pledge: The opposition must be as strong as when Anwar Ibrahim put it together in 2008. That is the kind of opposition we want to see," she said.

Amanah’s Sepang MP Hanipa Maidin made a special appearance at the gathering and said he concurred with Ambiga's call for a united opposition.

"Do not let it get to a point where we do not know who is our common enemy.

"BN is our enemy and so we must unite against it to face the next election," said Hanipa (photo), who underwent surgery in April to treat a stroke-induced brain haemorrhage.

Sitting on a wheelchair, Hanipa said he hoped to recover fully and return to Parliament for its next session in October.

"I am bored staying at home because there is no Umno, no Najib," he quipped.

PKR secretary-general Rafizi Ramli also recalled the united opposition against Anwar's first incarceration in 1998.

He said the supporters who were on the streets at the time must now, once again, demand for Anwar's freedom.

"We must free Anwar because he is the only one who can gather (and unite) all parties that now may not be able to sit down at the same table," Rafizi said.

"If we really want to bring down Najib and Rosmah, we must go back to our roots..." he said, citing the opposition's past successes under Anwar's leadership.

Since Anwar's incarceration, the Pakatan Rakyat federal coalition has been replaced with Pakatan Harapan.

This was after PAS-splinter Parti Amanah Negara was formed following an earlier clash between PAS and DAP.

PAS has also formed an opposition third bloc with Parti Ikatan Bangsa Malaysia.

The last Sarawak state election and the two by-elections in Sungai Besar and Kuala Kangsar saw BN boast thumping victories.

The situation, particularly in Sarawak, was partly attributed to federal opposition Harapan's failure to resolve issues surrounding seat negotiations among its member parties.