WASHINGTON (Reuters) - A future U.S.-UK trade agreement must incorporate strong provisions on worker rights, environmental protection, and enforcement to ensure bipartisan support, U.S. House Ways and Means Committee Chairman Richard Neal said on Friday, staking out a claim for Congress to help shape any such accord.Neal, a Democrat, said he expected to work closely with U.S. Trade Representative Robert Lighthizer in forging a new U.S.-UK trade deal after Britain's left the European Union on..