LONDON - Britain is set to break international law by bringing forward legislation to unilaterally change the Northern Ireland protocol that governs trade after Brexit, the president of Ireland's Sinn Fein party said on Sunday.

Mary Lou McDonald said there were mechanisms to improve the application of the protocol involving Dublin and Brussels.

"There is a willingness here, there is a willingness to engage by the European Commission, but the British government has refused to engage," she told Sky News.

"It has not been constructive, it has sought a destructive path, and is now proposing to introduce legislation that will undoubtedly breach international law."

(Reporting by Paul Sandle; Editing by Catherine Evans)