Goa Pradesh Congress committee president Subhash Shirodkar told PTI that D'Sa will file the nomination tomorrow and he enjoys backing of majority voters from the constituency.
"We have fielded local candidate. He is a strong contender. We will surely win this seat", a confident Shirodkar said.
The seat fell vacant after the demise of BJP legislator Matanhy Saldanha.
Shirodkar said the Congress stands united in support of their official candidate. "Cortalim people will realise and will vote for the candidate", he said, referring to the verdict in March 3 poll, which went against the party.
He said former minister Churchill Alemao will also support the candidate. "Alemao is still in Congress and he will campaign for the party in the constituency", he said.
In the run up to Cortalim by-poll, Alemao had shown keen interest to contest from the constituency.
However, the Congress party had refused him the ticket saying that they will go by the candidate staying within the constituency.