An Umno minister has warned those voting in the Rompin and Permatang Pauh by-elections that Pakatan Rakyat is opposed to the Prevention of Terrorism Act (Pota).

Therefore, Abdul Rahman Dahlan said ballots must be cast against the opposition's "soft stance against terrorism".

"It is clear Pakatan is so disconnected with the wishes of the people who insist on security and peace as priorities.

"Recent arrests by the police to prevent potential terrorist attacks in our country show how wrong Pakatan's opposition towards Pota is," he tweeted.

The housing, local government and urban-wellbeing minister was referring to the arrest of 12 individuals and seizure of explosive material.

Those arrested were said to be linked to the Islamic State and planned attacks on government buildings.

Home Minister Ahmad Zahid Hamidi said the suspected militants were also plotting attacks on Parliament.

Not 'principalists'

Meanwhile, Abdul Rahman lamented that peace and security were not Pakatan's top priorities.

He also lambasted Pakatan for being "willing to say anything and everything to get votes" in the by-elections.

"Mere populists than 'principalists'. Detrimental to the country, long term," he tweeted.

Concerns over POTA ranged from violation of human rights to detention without trial, with some claiming that it rekindles the spirit of the now defunct Internal Security Act (ISA).

However, the government has denied that POTA resembles the ISA and argued for its needs to combat terrorism.

The legislation was passed in the wee hours of April 7.

The Rompin by-election would be held on May 5 whereas the contest for Permatang Pauh would take place two days later.