Canadian diplomats working in the US have been directed to stay away from candidates running in the midterm elections, and to keep a low profile to avoid allegations by the Trump administration of political interference, people familiar with the matter said.

Under written guidance distributed Tuesday, Canadian officials are barred from meeting with or even being in the same room as midterm candidates — all House candidates and a third of the Senate — unless given special permission.

Canadian officials are still allowed to conduct other business and meetings with elected US representatives who are not up for reelection, if necessary. But they’ve been told to ensure they don’t appear in photographs alongside any elected US officials, according to people who spoke on condition of anonymity to describe the internal memo, which called the measures a “very risk-averse approach.”Nearly 500 Canadian diplomatic staff work in the US, including at its embassy in Washington and across 12 consulate offices in cities such as Detroit, Los Angeles, Dallas and Atlanta. The measures apply until the midterm vote on Nov. 3. The guidance is a sign of the highly charged atmosphere as President Donald Trump’s party faces the prospect of a resounding midterm defeat.

The House is seen as virtually certain to swing to Democrats, while the Senate — once seen as a firewall of sorts for Republicans — looks to essentially be a tossup. With Trump’s approval ratings hovering near a record low, Republicans are being forced to actively campaign in what would otherwise be safe Senate seats, such as Kansas and South Carolina.

Voting is already under way in many key states. Canada’s foreign affairs department didn’t immediately provide a comment in response to a request from Bloomberg. Trade talks between the US and Canada collapsed two months ago, even after Trump had announced a preliminary deal, and formal negotiations have not yet resumed.

Trump has since threatened to hike tariffs on Canadian autos to 50%, up from 25%, on Jan. 1, a deadline that may prompt a renewed round of discussions later this year. Those would occur at the same time as the so-called lame-duck session of the current, departing Congress. Prime Minister Mark Carney and other Canadian officials have frequently made the case that US tariffs punish American consumers and businesses — but Trump administration officials have been aggressively pushing back, warning Canadians not to speak out.

On Wednesday, Carney and Ontario Premier Doug Ford rejected the idea that their advocacy against US tariffs was inappropriate.

“I have no interest at all in interfering in American elections,” Ford said, adding that he lived in the US for 20 years and “loves the American people.”

Carney said the White House initiated the trade war and Canada is simply responding. “All of our actions are in the interest of Canadian workers, Canadian families and the future of this economy,” he said.

The guidance to diplomats came shortly before the US embassy in Canada posted a “fact sheet” on Wednesday alleging a concerted effort by Canada to sway the American election toward a friendly outcome. The document outlined a series of comments by Canadian politicians — particularly Industry Minister Melanie Joly — that suggested Canada targeted Republican-held states with pressure tactics, including counter-tariffs that hit exporters in those regions. “All Canadians should refrain from attempting to participate in or influence US elections in any way. Americans decide America’s elections,” the embassy said.

The fact sheet also pointed to last year’s TV ad campaign by the Ontario government. The ad, which ran on US broadcasts of baseball’s World Series, quoted former President Ronald Reagan making the case for free trade. It infuriated Trump, leading him to terminate trade talks with Canada.

Republican candidates in the US have been under siege over affordability concerns during the midterm campaign, and Trump’s tariffs on Canadian goods have been an election issue in key battleground states such as Maine and Michigan.

Although most US-Canada trade remains tariff-free, certain sectors in Canada have been badly hurt by Trump’s tariffs — particularly the aluminum, steel, auto manufacturing and lumber industries.

Over the summer, Canadian and US officials spent weeks in intensive trade negotiations that would have lowered some of those tariffs, but the talks fell apart on Aug. 21 when Carney pulled his negotiators away from the table.

Trump then placed new tariffs of 50% on about $20 billion worth of Canadian items. He later imposed further measures that included banning the import of some Canadian alcohol and restricting Canadian firms from bidding on US government contracts.

Canada responded with its own set of 50% counter-tariffs on some categories of US-made goods.

Officials on both sides have remained in contact since then, and Carney said he and Trump had a lengthy phone call on Wednesday morning that included a discussion of trade. But there’s no sign yet of a resumption of formal negotiations.