BRUSSELS (Reuters) - The European Union and Britain on Monday announced additional agreements on the contentious Irish border backstop in a bid to make their stalled Brexit deal more palatable to the House of Commons.

British Prime Minister Theresa May and European Commission President Jean-Claude Juncker arrive for a news conference in Strasbourg, France March 11, 2019. REUTERS/Vincent Kessler

UK lawmakers will vote on Brexit for a second time on Tuesday after already defeating the tentative agreement in January over fears that the backstop - an insurance policy to avoid extensive border checks on the island of Ireland after Brexit - could trap their country in EU trading rules for ever.

The following are some elements of the new “instrument” published by the sides late on Monday:

- The EU and UK agree to swiftly start talks on a new trade deal after Brexit. They stress they do not want the backstop to kick in. Should that happen, both are “determined” to agree a different way of maintaining the open Irish border to replace it.

- The sides agree to a “regular” review of their agreements on the Irish border. They say the so-called Vienna Convention on the Law of Treaties, an international law on legal agreements between states, is a reference in any disputes.

- Sides will use “their best endeavors” to agree a trade deal to obviate the need for the backstop by the end of 2020.

- “A systemic refusal to take into consideration adverse proposals or interests” would amount to a breach of the EU-UK agreement.

- The EU and Britain “will start negotiations on a subsequent agreement as soon as possible after the United Kingdom’s withdrawal from the Union. Those negotiations should be conducted as a matter of priority, and efforts redoubled should the negotiations not be concluded within 1 year” after Brexit.

- The sides also commit to “working speedily” to agree by end-2020 alternative arrangements to the backstop.

They will analyze comprehensive customs cooperation arrangements, facilitative arrangements and technology solutions, which have all been UK demands.

- The EU and UK to convene a “high-level conference” twice a year to assess progress on trade and alternatives to the backstop.

- If an arbitration panel rules that the EU acts to have the backstop in place indefinitely, an arbitration panel would allow Britain for “a unilateral and proportionate suspension” of their customs union but in a way that would not endanger the open Irish border.