Prime Minister Stephen Harper made a surprise appearance at a barbecue hosted by Toronto Mayor Rob Ford on Tuesday evening.

Private remarks from the invitation-only event became public when some in attendance posted videos on the video-sharing website YouTube. The excerpts available suggest a warm and close relationship between the two leaders.

The mayor introduced the prime minister as the evening's special guest.

"He's my new fishing partner," Ford told the friendly crowd. "He took me up north a couple of weeks ago and I love to fish." The mayor good-naturedly bragged of catching a bigger fish than Harper did, a 39-cm smallmouth bass.

Harper paid tribute to the past political help his federal party had received from his host.

"Rob endorsed us in the election. That helped a lot," Harper said, amid warm bursts of applause from a partisan crowd that included some 700 Conservative campaign volunteers from the Toronto area.

The prime minister also said Ford was "doing something very important that needs to be done here. He's cleaning up the NDP mess in Toronto."

Harper didn't stop there, putting in a campaign plug for Ontario's provincial Conservatives in this fall's election.

"We started cleaning up the left-wing mess federally in this area. Rob's doing it municipally. And now we've got to complete the hat trick and do it provincially as well."

Ontario MPs Patrick Brown and Kellie Leitch organized the event, billed as an appreciation night for Finance Minister Jim Flaherty, the cabinet minister responsible for the Greater Toronto Area. The prime minister's attendance was intended to be a secret.

Flaherty joked in his speech that the Conservative party's GTA caucus used to meet in a phone booth in Ottawa. "Now we had to find this big committee room in Centre Block to accommodate all the people from the Greater Toronto Area, which is fantastic," Flaherty said.

Flaherty is said to be close to the mayor and his politically active family. Ford thanked Flaherty for his friendship and loyalty in his introduction.

Harper thanked the mayor's mother Diane for her hospitality, saying he'd heard about previous events the family hosted in its home. He also thanked the mayor's mother for "giving us this great Conservative political dynasty that we have here with the Fords."

The mayor's brother Doug is a city councillor in Toronto.

The invitation-only event was not publicized to the national media, but at least one newspaper chain received a tip and managed to snap a photo of the prime minister's arrival.