Sir Keir Starmer will declare people-smuggling, terrorism, climate change and weakening democracy the four major threats to western countries as he embarks on the latest in a series of engagements on the global stage.

The Labour leader will say the joint challenges make up an “axis of instability” during an appearance at a summit for “progressive” politicians in Canada over the weekend.

Following his insistence during a trip to The Hague that closer co-operation with the EU is key to tackling organised immigration crime, he will argue that internationalism is the best protection against all four threats.

Sir Keir will be joined by shadow foreign secretary David Lammy at the summit in Montreal ahead of an expected visit to Paris next week to meet French president Emmanuel Macron.

The flurry of international engagements has been seen as a bid to appear statesmanlike and burnish his leadership credentials ahead of a likely general election next year.

Labour officials are emphasising Sir Keir’s background as a director of public prosecutions in making the case that he could manage organised immigration crime if handed the keys to No 10.

No 10 appeared to downplay the significance of the Opposition leader’s expected Paris trip, saying it was “not unusual”.

But Sir Keir could also be eyeing a White House meeting with US president Joe Biden in the coming months, whose “Bidenomics” and landmark green subsidy push has attracted admiration from Labour.

Canadian PM Justin Trudeau, Norway’s premier Gahr Store and Jacinda Ardern, former prime minister of New Zealand, are among other leading politicians expected at the event this weekend, where Sir Keir is to set out his foreign policy stance.

A political row has broken out following Sir Keir’s indication that Labour would seek an EU-wide returns agreement which would involve taking a quota of migrants from the bloc.

The Tories have seized on the suggestion of closer ties to Brussels, claiming that any such arrangement could lead to 100,000 EU migrants coming to the UK every year.

As well as attacks from the right, Labour faced criticism from Matt Wrack, the president of the Trades Union Congress, who told The Guardian Sir Keir was in “danger of pandering to right-wing Tory rhetoric” on immigration.

Labour dismissed the 100,000 figure as “total garbage” and insisted any partnership would focus on children with family in Britain rather than formally joining the EU’s official quota scheme.

The party said it would deepen intelligence ties with the EU and station more British police on the continent as part of efforts to “smash the criminal gangs” profiting from small boat crossings.