The Land Transport Authority (LTA) is still studying whether the future Cross Island Line (CRL) can be extended from Pasir Ris to Punggol.
Transport Minister Khaw Boon Wan yesterday said in a written parliamentary reply that engineering studies are ongoing for this proposed stretch of the CRL.
Mr Gan Thiam Poh (Ang Mo Kio GRC), had asked if the Thomson-East Coast Line (TEL) could be extended to connect to Pasir Ris and Punggol, to provide greater connectivity for residents in these areas.
Mr Khaw, who is also the Coordinating Minister for Infrastructure, said there are no plans to extend the 43km line - which will end at Sungei Bedok once completed in 2024 - to the two towns.
However, the LTA is studying the feasibility of extending the CRL to serve Punggol, he added.
The first phase of the line, which was announced last month, will have two stations in Pasir Ris estate, one that will be an interchange station with the East-West Line and another at Pasir Ris East.
When the CRL was first announced in 2013, plans unveiled then had included a possible link between Punggol and Pasir Ris.
Connecting the two towns by MRT would cut travelling time - currently about 40 minutes by bus - to about 10 to 15 minutes, said the LTA back then.
But the first phase of the CRL, which will stretch across 12 stations from Changi to Sin Ming and be ready by 2029, did not include the possible link to Punggol.
The CRL, Singapore's eighth MRT line, will connect Changi to Jurong once fully completed.
It is projected to have an initial daily ridership of 600,000, which is expected to eventually grow to one million.
Two possible alignments for another stretch of the CRL are also being studied. Nature groups have raised concerns about one alignment that would see the line running under the Central Catchment Nature Reserve.
Mr Gan had also asked Mr Khaw whether the TEL could start service ahead of schedule.
In response, Mr Khaw said the timelines for rail lines are carefully planned so safety is not compromised. "It is unlikely that we can expedite the opening of the TEL further."