Having begun the week looking positive the Loonie came to grief on Wednesday when the Bank of Canada kept its benchmark interest rate steady at 0.5%. The rate decision itself was not the problem: it was the governor's statement that did the damage. He noted a "heightened uncertainty about trade policies in particular" and said "a rate cut remains on the table". Investors did not like the sound of either of those and the Canadian dollar became the week's feeblest performer, losing one US cent and falling by four and a half cents against sterling.
The pound's lucky break, surprisingly, was a speech by the Prime Minister in which she said Brexit would mean a clean break with the EU, otherwise known as a Hard Brexit. Because her main points had been leaked the previous evening it did not come as a shock. Investors were heartened that parliament would get a vote on the final deal.