Jack Stringer/Getty Images Amber Rudd suggests her government could perform a U-turn and keep Britain in the customs union. The Home Secretary refused to confirm Theresa May's current policy of leaving the customs union. Rudd is already under pressure to resign from the Cabinet over her handling of the Windrush fiasco. LONDON — Home Secretary Amber Rudd has refused to rule out Britain staying in a customs union after Brexit in a surprise break from UK government policy.