Prime Minister Theresa May will seek to head off moves for Scottish independence in a speech Monday as she finalizes her plans for triggering two years of negotiations to leave the European Union. In a trip north of the border, May will appeal to Scottish voters to keep the U.K. intact. She’ll kick-off the Brexit process two days later in a letter to the bloc and on Thursday set out proposals to bring thousands of EU regulations under U.K. control. “As Britain leaves the European Union, and we forge a new role for ourselves in the world, the strength and stability of our union will become even more important,” May will say in the speech, according to extracts released by her office. “When this great union of nations—England, Scotland, Wales and Northern Ireland—sets its mind on something and works together with determination, we are an unstoppable force.” The prime minister will signal her intention to act quickly on Thursday when she publishes detailed plans of her Great Repeal Bill, which is intended to convert EU law into British law and provide continuity in the months after Britain leaves the bloc. The bill will include powers for ministers to change regulations as they’re converted to U.K. statutes, which the government says is essential to remove references to European institutions and smooth the transition. Jeremy Corbyn, leader of the opposition Labour Party, said he’ll challenge the proposed “correcting” powers, which the Department for Exiting the European Union said would be temporary, indicating headwinds for May as she maps out her strategy. “We need total accountability at every stage of this whole Brexit negotiation,” Corbyn told ITV’s “Peston on Sunday” show. “We’re not going to sit there and hand over powers to this government to override parliament, override democracy and just set down a series of diktats on what’s going to happen in the future.” While the constitutional detail may sound obscure, if May fails to get the powers she needs from parliament she could struggle to deliver favorable Brexit conditions. A blockage might give her a reason to call an early general election, a prospect she has so far rejected despite her poll lead over Corbyn. Scotland Timing During her visit to Scotland, May will meet with First Minister Nicola Sturgeon, who says Brexit justifies another independence referendum. While May says it is not the right time for Scotland to vote on quitting the U.K., Sturgeon announced on Monday she plans to travel to New York and California to boost Scotland’s profile and encourage U.S. investment. “Following the U.K.’s vote to leave the EU and the U.K. government’s decision to leave the single market, I want to reassure investors and visitors from the United States that Scotland is an outward looking, welcoming country and remains open for business,” Sturgeon said in a statement. May is also seeking investment as Brexit approaches, and a 400-strong delegation of business leaders and officials from Qatar will gather in London on Monday as the emirate prepares to announce major new investments in the U.K. At the same time there was a warning in Monday’s Times newspaper from Steve Woolcock, who has been training officials in the Department for International Trade, that there is a risk of rushing into politically motivated deals. “The greatest danger in trade policy at the moment is that there’s a political imperative to conclude agreements with other countries to show that Brexit works,” Woolcock, who teaches international relations at the London School of Economics, told the paper. “These are unlikely to have many economic benefits or enable the U.K. to keep up with other preferential trade agreements.”