FREDERICTON -- New Brunswick Premier Brian Gallant faces the unusual prospect of having to call a byelection weeks after he won the general election following the abrupt departure of one of his caucus members.

Gallant shed little light Wednesday on why Gary Keating announced he was quitting, other than to say it was due to concerns that the role of public life would have on his health and family.

"We certainly respect that he wants to put his health and his family first," Gallant told a news conference. "It was more that he came to the realization that this isn't the right time to be embarking on this endeavour."

Keating, who was elected Sept. 22 in the riding of Saint John East, announced in a news release late Tuesday he was resigning. He had not yet been sworn in as a legislature member.

"Over the course of the election, and during the past few weeks, it has become very apparent that the long hours and travel associated with the job would have a negative impact on my health and, especially, my family," Keating said in a statement.

He has not returned messages for comment.

Gallant was asked whether there were other reasons behind Keating's departure, such as being passed over for a cabinet position.

"It's absolutely no other reason except the fact that he wants to put his family and health first," Gallant replied.

The president of the New Brunswick Progressive Conservatives urged Gallant to immediately call a byelection.

"It's imperative that the people of Saint John East be represented," Jason Stephen said.

Stephen said Keating's announcement was unprecedented and raises questions about how the Liberal party vetted its candidates.

"I would have thought that they would have gone through a more detailed process with their candidates," he said.

Keating narrowly won the riding over Progressive Conservative candidate Glen Savoie. A judicial recount later confirmed he won by nine votes.

Savoie said he was shocked to hear of the resignation.

"My next thoughts went to 'Is everything OK with him health-wise?"' he said. "I hope all is well with him and I certainly wish him the best from that regard."

Savoie said he intends to run again in the riding.

Gallant has up to six months to set a date for a byelection once a vacancy is declared but Savoie said it should be held much sooner.

"You can't have people going six months without representation," he said.

Gallant said he would need to discuss the date of a byelection with his cabinet first, though he added that he would like to have it before the legislature convenes in early December.

"You can be certain that we're going to want, as much as possible, to have Saint John East represented when the legislature is in session," Gallant said.

Keating's resignation leaves the Liberals with 26 seats. The Progressive Conservatives have 21 members and the Greens have one seat.