John Efford has raised questions about whether Liberal Leader Yvonne Jones should stay on for the October election. (CBC)

A former Liberal heavyweight in Newfoundland and Labrador has cast doubts whether ailing leader Yvonne Jones should take the party into the fall election.

But John Efford, who held provincial and federal cabinet posts, stopped short of calling on Jones to resign as leader, even though he says it's clear what she ought to do in the face of poor polling results.

"Yvonne is a great person, she's been a great leader in the Opposition, but unfortunately the people of the province — they're the ones who speak," Efford said during a panel discussion on the St. John's Morning Show on CBC Radio.

Efford cited the byelection results this week in Humber West, in which the party fielded prominent candidate Mark Watton but still trailed far behind PC candidate Vaughn Granter.

Yvonne Jones said earlier this week she is confident about the Liberal campaign heading into the fall. (CBC)

Efford also said a Telelink poll released this week by NTV, in which 11 per cent of respondents preferred Jones to lead the province, as more damaging to her prospects.

"Yvonne Jones unfortunately does not have good health and people just don't see her as the next premier of Newfoundland and Labrador," Efford said.

"If I were 11 per cent in the polls, I know what I would do, and that's what you have to look at - what is in the best interest [of the party]. Right now, the people have spoken very clearly in the byelection but the poll itself that came out a day or so ago speaks even clearer," said Efford, who represented Port de Grave in the house of assembly for 16 years, and later represented Avalon riding in the House of Commons.

Last August Jones announced that she was diagnosed with breast cancer.

Thursday, Jones dismissed Efford’s comments and called him a "nuisance."

"There are people out there like John Efford that have been nothing but an absolute nuisance in recent years to the Liberal Party and I don't expect that attitude is going to change any time soon,"

Jones says she's gotten nothing but support from active Liberals and she doesn't count John Efford among them.

"I just see John Efford as an individual who has aspired to be in the position I am in today, never quite made it and have not really gotten over it," she said.

Jones told CBC News that she intends to lead the party in October's general election.

"I'm hoping to be back full time as we move into the legislative session in the spring. I don't see an issue with it at all," said Jones, who temporarily stepped aside as leader to focus on her cancer treatment.