LONDON (Reuters) - The British government has broken its promises to Northern Ireland’s Democratic Unionist Party and put pressure on the arrangement that keeps Prime Minister Theresa May in power, the party’s Brexit spokesman said on Wednesday.

The DUP, which props up May’s minority government, is angry over the so-called backstop arrangement in the deal for Britain to leave the European Union, saying it essentially splits Northern Ireland from the rest of mainland Britain.

“We had an arrangement to keep the government in power ... promises were made,” Wilson told parliament, saying May had promised his party that Northern Ireland would get a final say in whether such a backstop was put in place.

“There has been bad faith, the agreement and the understanding we had has been broken ... that has caused tension and going down this road will create further tensions. We want to see the agreement honored because we want to see the United Kingdom preserved.”