Umno man Jamal Md Yunos is the latest to be sent packing from a Sarawak airport, after being barred from entering the state.

He is to arrive in Kuala Lumpur at 4pm.

The Sungai Besar Umno division chief is believed to be the first Umno leader to be barred ahead of the Sarawak election on May 7.

Sarawak Chief Minister Adenan Satem defended the immigration ban by saying he is safeguarding state harmony.

Jamal last year led the ethnically-charged Himpunan Rakyat Bersatu, popularly known as the red-shirts rally, which saw protestors breaching police lines to storm Petaling Street, a traditional ethnic Chinese trading area.

Sarawak has immigration rights, according to the 1963 Malaysia Agreement.

Penang executive councillor Afif Bahardin was at midnight also barred from entering Sarawak.

The PKR leader is the second Penang exco member refused entry.

After arriving at the Kuching International Airport, Afif received a notice from the state Immigration Department as his name has been blacklisted.

According to him, the instruction to bar him from entering Sarawak came from higher-up.

"Such an act only shows that the state BN leadership is a regime that will not hesitate to grab the people's rights when its powers are under threat," he said.

"This also shows it does not appreciate the principle of the formation of Malaysia," he said.

"We call on the people in Sarawak to vote for a change in the state election," he added.

So far, at least 37 opposition lawmakers, activists and academicians have been banned, including PKR vice-president Nurul Izzah Anwar, PKR secretary-general Rafizi Ramli and Amanah president Mohamad Sabu. Clare-Rewcastle Brown, editor of Sarawak Report, is also on the list.

Opposition lawmakers have contended that travellers engaged in legitimate political activities allowed under Section 66 and 67 of the Immigration Act and are considering taking legal action.

The state Immigration Department had declined to reveal the full list of those barred from entering the state.

"We would indulgently advise that if you feel you might be an undesirable person in Sarawak, you should not come," said Sarawak immigration director Ken Leben.