The Singapore Democratic Party (SDP) chairman Jufrie Mahmood was the first visitor at the Elections Department on Saturday morning.
He was spotted at 8.45am entering the Prinsep Street building. He later emerged and told reporters he had submitted two applications for political donation certificates, a prerequisite for standing in an election.
These are declarations that candidates have not accepted foreign or anonymous donations of $5,000 or more, among other things.
He did not say who the applications were for, but said: "candidates will be revealed soon".
He also said that the Workers' Party has not responded to SDP about its proposal to conduct a joint campaign where a SDP candidate would be fielded.
If elected, the candidate would push SDP policies in Parliament and chair the town council, while the WP would run the council's daily operations.
The WP, however, told The Straits Times in a statement early on Saturday morning that it has "noted SDP's proposal" and will stick to its plans to "offer a choice to voters in Punggol East".