Former Prime Minister Dr Mahathir Mohamad and a few other Malay BN bigwigs are due to turn up the heat in Hulu Selangor as the by-election campaign enters the crucial final lap.

NONE Mahathir (left) , who had previously declared that he had no interest in being involved in the campaign, will be delivering a speech at 8.30 in Serendah tonight.

This will be his first campaign outing in a year. He last campaigned in the Bukit Gantang and Bukit Selambau by-election. BN lost on both occasions.

Mahathir was the first former premier to join in BN's campaign. The closest comparison is Tunku Abdul Rahman who campaigned for the now defunct Semangat 46 in 1990.

Mahathir's visit follows that of Prime Minister Najib Abdul Razak, who had four stopovers last night, immediately after his return from Japan.

This morning, his wife Rosmah Mansor also joined the fray by launching the ‘Touch of 1Malaysia' program at Kampung Felda Soeharto in Hulu Bernam.

Najib is scheduled to have more programs in the constituency all the way up to the eve of polling day.

The intensity of the Najib's campaign there has raised eyebrows because it could signal a lack of confidence on part of BN.

On the Pakatan Rakyat front, PAS spiritual leader Nik Aziz Nik Mat would be making his presence felt tomorrow as he is scheduled to hold a lecture at the Kuala Kubu Baru mosque, followed by a speech in Changkat Asa, Ulu Bernam.