Jack Layton won't be in attendance when the NDP holds its summer caucus retreat in September to set out the direction and strategy for the fall Parliamentary session beginning less than a week later.

The meetings in Quebec City will take place from Sept. 13-15 before the scheduled return of Parliament on Sept. 19.

An NDP spokesperson confirmed the NDP's interim leader Nycole Turmel will be leading the summer caucus meetings on behalf of Layton, who announced in July he is waging a new fight against cancer.

"It's always been the plan for Mr. Layton that he intended to return on the 19th and in his July 25 statement it was always assumed that the interim leader would handle the caucus retreat," NDP spokesperson Kathleen Monk told CTVNews.ca on Wednesday morning.

A frail-looking, gaunt and hoarse-sounding Layton held a news conference on July 25 to announce he would be taking the rest of the summer off to undergo treatment for the new, undisclosed form of cancer.

Layton had earlier been diagnosed with prostate cancer.

He said his goal was to return to work on Sept. 19. Monk said that is still the plan.

"Mr. Layton is really grateful for the support and messages and gifts he has received from Canadians all across the country. He draws a lot of strength and inspiration from that but he's asked that he have his privacy to rest and recuperate and receive treatment, with his family," Monk said.

Federal political parties typically use their end-of-summer retreats to plan the direction and tone the party will take in the fall.

However, Monk said the real work doesn't begin until MPs are back on Parliament Hill.