The opposition may have set its eyes on Johor in the next general election but Prime Minister Najib Abdul Razak is not taking it lying down.

Attending a grand Hari Raya open house in Sembrong tonight, Najib was flanked by top Umno leaders including vice-president Hishammuddin Hussein, who is the constituency's MP.

Najib's purpose was clear as he declared: "We come here today to ensure that the land of Sembrong will remain firmly in the hands of BN".

The prime minister then went on to say that he would "pay the bills" for the people of Sembrong, but requested that they also repay him.

"Today, coming here should have been free, there shouldn't be a need to pay anything.

"But looks like Hishammuddin had sent me the bill even before I arrived here... I was cornered," he said in jest.

Najib then announced the construction of 1,000 units of people's public housing in two phases, 500 homes for second generation Felda settlers and the upgrading of Taman Sri Lambak police kiosk into a full-fledged police station.

"So, with three projects, I have paid the bill for this meeting with the people of Sembrong. I have fulfilled your wishes, now you'll need to fulfil mine," he said.

Najib subsequently asked what his wish may be, to which the audience at Taman Sri Lambak stadium responded that it was to win Sembrong.

The gathering tonight was a show of force for Najib, who was also flanked by Umno acting deputy president Ahmad Zahid Hamidi, Johor Umno chief Mohamed Khaled Nordin and Umno supreme council member Mohamed Nazri Abdul Aziz.

The gathering was aired live on Najib's Facebook page.

This came just five days after Pakatan Harapan said it hoped to pick up several more parliamentary seats in Johor including Sembrong, Johor Baru, Pasir Gudang, Tebrau, Tanjung Piai, Labis, Segamat, Sekijang, Pulai and Sri Gading.

Earlier in his speech, Najib also took an indirect jab at Harapan's move to formalise its leadership structure with PKR's Anwar Ibrahim as de facto leader, Dr Wan Azizah Wan Ismail as president and former premier Dr Mahathir Mohamad as chairperson.

Najib zoomed in on the fact that the coalition did not have a clear head.

"Don't pawn our future by choosing those who are confused and do not know who is their towkay.

"Everyone seems to have a position but we don't know who the boss is," he said.

The proper choice, Najib added, was one that is stable and with a track record, namely BN.