At a recent discussion with the elections commissioner, several proposals in that regard were submitted, but the only proposal that can be implemented without a re-demarcation of the electoral divisions is the one agreed upon by the SLFP, he said.
Senaratne has told BBC Sandeshaya that his party hoped the next general election would take place under this system.
This system will increase the number of parliamentary seats to 250.
The SLFP parliamentary group has decided that the 19th amendment to curtail powers of the executive president and the 20th amendment to introduce electoral reforms should be presented and adopted simultaneously.
Senaratne, also the cabinet spokesman, said the 20th amendment would soon be tabled in parliament, and conceded that as a result, the dissolution of parliament could get delayed.