Prime Minister Dr Mahathir Mohamad's invitation to Malay politicians to join Bersatu has come a little too late, said Umno veteran Nazri Abdul Aziz.

"Maybe it's a little bit too late as we (Umno) have agreed to work together with PAS," he told media at the Parliament lobby.

The former minister said there was no turning back from the alliance between both parties, as they had won three by-elections since last May, and aimed to win the next general election.