TRAVELLING around the Johor Baru area this week, I was struck by how diverse the city's make-up now is.

Walking around the streets near the Causeway and City Square, and trailing several candidates on their rounds further afield ahead of the upcoming General Election, I stopped to ask store assistants, waiters and others what their sentiments were.

This may not be an accurate numerical representation, but one in five said they were not citizens.

Over the past decade, workers from Bangladesh, China, Indonesia, Myanmar, and Nepal, to name just a few countries, have settled in the state to do jobs that few locals want to do because of the hours and pay.

They are found not just in the middle of the city, but further afield in districts like Kulai and Muar, to the north of Johor.

And as campaign fever heats up, their presence has become an election issue that could flare up.

It is not, however, so much about whether they are taking up scarce land or depressing wages - many do low-paying jobs few locals are willing to take on - but about their status.

Those I spoke to said they were not Malaysians, but knew several of their friends who had stayed long enough, decided to sink roots here, and have been given citizenship over the years.

The opposition has charged that this project of giving citizenship aims to boost support for the ruling Barisan Nasional coalition, as new voters are more likely to feel indebted to the government, although this allegation is hard to prove.

Now, these new citizens have become the target of several pro-opposition supporters who threaten to take vigilante action against them on polling day.

On Thursday, the Federal Police issued a stern warning to parties and individuals against taking the law into their own hands and attempting to intimidate voters.

"There have been subtle messages which police have detected," Assistant Commissioner Ramli Mohamed Yusof told reporters, warning that threatening voters is an offence.

In some cases, the messages have not been so subtle: a group calling itself Anything But Umno (ABU) says it will activate a special squad to ensure foreigners given MyKad (Malaysian ICs) do not vote on May 5.

ABU has, in recent months, produced leaflets in Bengali, Indonesian, Myanmar and Urdu and distributed them in neighbourhoods, warning nationals of Bangladesh, Indonesia, Myanmar and Pakistan not to turn up to vote.

These four are among the largest countries of origin for foreign residents in Malaysia.

"On polling day, Malaysians will patrol polling stations to prevent any form of cheating," the poster says. "If you come to polling stations, prepare to face the wrath of Malaysians," they say.

The message in Indonesian goes further to say that supporting BN is akin to supporting the wrongdoings against Indonesian migrant workers in Malaysia.

ABU spokesman Haris Ibrahim told reporters in KL last week some 40,000 leaflets had been distributed. They have also been circulating on social media and online.

Mr Haris claimed that checks on the voter list showed some 253,000 names had a code that signified they were born abroad, and alleged that two million foreigners had been given ICs.

His claims have been criticised, with officials noting that a new Malaysian citizen is still a Malaysian with full rights, including that to vote, and any attempt to deprive them of this right was against the law.

But at least one candidate has a different take on the matter.

Parti Keadilan Rakyat (PKR) candidate for Muar, Mr Nor Hizwan Ahmad, told me the presence of several thousand foreign workers in the seat he is contesting has long been a bane of residents.

Some get into fights, and the poorer areas they live in are disorderly.

But his district is also one with several thousand residents of Javanese descent who still speak the language though they have been in Johor for several generations, and he has come out with posters telling them to vote for change in the language.