Boris Johnson faces a pivotal week: deliver a trade deal with the European Union or risk a major rupture, and avoid a rift with U.S. President-elect Joe Biden over the U.K.’s controversial Brexit legislation.

After eight months of negotiations between the sides, Johnson and European Commission President Ursula von der Leyen used a phone call over the weekend to plot the way toward a trade deal ahead of the Nov. 15 deadline set by both parties.

Major differences still need to be bridged on the same issues that have plagued talks from the beginning: so-called level playing field rules for business and access to British fishing waters.