The Singapore Democratic Party raised eyebrows on Friday when it called a press conference to propose a unique joint venture with the Workers' Party (WP).
But the Reform Party said it made a similar offer earlier.
RP chief Kenneth Jeyaretnam was on a walkabout in Punggol East when he heard the news of the offer made by the SDP.
He said: "We've already proposed something very similar to them (WP) ... given WP's experience running town councils." He said the offer was made last week but declined to reveal further details.
The plan put forward by the SDP suggests that the party and WP work together on a single campaign, supporting a single SDP candidate. In return, if the SDP candidate won the election, SDP would let WP run Punggol East Town Council.
On Friday, Mr Mohamad Affendy Abdul Rahim, 56, a founding member of RP alongside Mr Jeyaretnam's father, the late JB Jeyaretnam, also said that the party had suggested loaning the RP chief to the WP as a candidate: "It's always good to cooperate with other parties. We don't want friction. We're willing to loan our best man to WP."
He added: "WP has all their best men in Parliament already. They should let the son of JBJ in Parliament."