King Charles.
"It's going to be very affirmative of Canadian sovereignty. And I can say personally that it's something that King Charles will celebrate saying. I have no doubt," says Mr Kinsman, who worked as a diplomat with the King when he was Prince of Wales.
"It will say the government will protect, pursue and preserve the sovereignty of Canada as an independent state," he predicts about the speech, which follows an election won by Mark Carney on a wave of anti-Trump sentiment.
The King's mother, the late Queen Elizabeth II, was the last monarch to open Canada's Parliament in 1957 and was also the most recent to deliver the "speech from the throne" in 1977, in a ceremony that marks the start of a parliamentary session.
She began that speech with a few of her own personal comments - so there is scope for the King to add his own thoughts.
"I don't know what pronoun they'll use. He'll be talking about the 'government proposes'. But I don't know if they'll throw in an "I". Either way he'll be identified with it," says Mr Kinsman about the personal nature of this speech from the King in Canada - a Commonwealth country and Nato partner.
It's going to be a more dressed-down event than the pomp of the Westminster state opening of Parliament. The King will be in a suit rather than a gown and crown, reading a speech that could last about 25 minutes, much of which will be about the government's legislative plans.
There are also likely to be nods to the importance of Canada's First Nations communities, in a speech that comes on the first visit to Canada from King Charles and Queen Camilla since the start of their reign.
The King, invited by Mr Carney, will have to balance a message of solidarity with Canada, without jeopardising the UK's relationship with the US.
"The King has long experience and great skill in walking that diplomatic tightrope," says a royal source.
"He's held in high regard around the globe and across the political spectrum, with good relations with world leaders who understand his unique position."
Mel Cappe, a former Canadian minister and senior civil servant, has been involved in preparing such speeches from the throne, usually delivered by a governor general.
He expects the King to add a "few paragraphs of his own at the beginning" to "give his own personal view", but the overall text of the speech will be approved by Canada's prime minister and his officials.
"He's not going to poke President Trump in the eye. That would cause a problem for Canada. On the other hand he isn't going to suck up to Donald Trump," says Prof Cappe, who was also a high commissioner to the UK.
He believes this intervention could have a big impact: "Symbolically this is huge. President Trump has a lot of admiration for the monarchy. He is impressed by the royals."
This royal moment will be a platform for Canada's government to talk about tariffs and to mention the visit to the White House where PM Carney said Canada would "never" be for sale, says Prof Cappe.
"So somewhere in that speech, look for the word "never"," he says.
President Trump, as shown in his recent controversial White House meetings with South Africa's President Ramaphosa and Ukraine's President Zelensky, can be an unpredictable diplomatic partner.
"The old alliances are breaking down," says Mr Kinsman. And against a background of such uncertainty, King Charles has been part of an unexpected international balancing act.
He became a key part of the charm offensive to maintain the UK's good relations with President Trump, with an invite for a second state visit. Now he's going with a message of reassurance to the Canadians.
Sir Keir Starmer has been using the King to get closer to Trump, while Mark Carney is using him to keep Trump further away.
"He isn't anybody's tool or fool. This is something that he believes… It genuinely is something that he wants," says Mr Kinsman about the King's support for Canada.
The former diplomat remembers how much the then Prince Charles showed a personal affection for Canada and a sense of duty towards its people. A planned trip last year had to be cancelled because of his cancer diagnosis.
