Sacked former deputy prime minister Anwar Ibrahim will led the opposition assault in a forthcoming by-election as he gears up for a return to formal politics, an official with his party said today.

The Election Commission today set April 28 as the date for the by-election in the state seat of Ijok in Selangor, called after a lawmaker from the ruling Barisan Nasional coalition died last week.

"Anwar will be participating in the campaign and we expect better support this time," said Syed Husin Ali, deputy president of the Parti Keadilan Rakyat, which Anwar advises.

The last state election was in 2004, when the PKR lost Ijok by a narrow margin of 1,649 votes to the ruling BN coalition.

Both the sides have said they would contest the seat.

"We will be fighting as an underdog, with very little money and hardly any media coverage, but having Anwar on our side is a great asset," Syed Husin told AFP.

Running for presidency

Anwar was the heir-apparent to former leader Dr Mahathir Mohamad until 1998, when he was sacked after facing sodomy and corruption charges that landed him in jail for six years.

Anwar's sodomy conviction was overturned but the corruption verdict still stands, barring him from standing for public office until April 2008.

However, Anwar has said he planned to run for president of the party - a position currently held by his wife, Wan Azizah Wan Ismail - when the party holds its annual national congress at the end of May.

Syed Husin said Anwar had already returned to the political scene in recent months and that the campaigning in Ijok would be another marker in Anwar's political comeback.

"Certainly he has returned to full-time politics," he said.