European leaders have put it up to the UK by stressing the Brexit draft withdrawal agreement is the only deal on the table.
Taoiseach Leo Varadkar has come out strongly to say "there isn't a plan B" adding that the deal signed off on today is "the best deal that is available".
The EU 27 and British prime minister Theresa May met for a special Council Summit in Brussels this morning where they endorsed the agreement as well as the political declaration around future relationship talks.
The pressure is now on Mrs May who will have to convince politicians in the House of Commons to ratify the deal.
Speaking after today's meeting, Mr Varadkar said the best outcome would be for the UK to stay in the EU but said the agreement is "the next best outcome".
"In terms of alternative options and a plan B, let's not forget what we have here, we have an agreement that took between 18 months and two years to negotiate, it's is over 500 pages long and as of today has the support of 28 Governments."
Mr Varadkar said that he has heard "a lot of people talking about better deals or alternative deals" but moved to shut this prospect down by stating that "what's on the table is the only deal".
"The entire European Union today was very much of the view that there couldn't be a renegotiation, it wasn't easy to get to this point, a 500-page treaty that has been ratified by 28 States all at once."
Mr Varadkar added: "What we need to do now is get on with it, get on with ratification of this agreement by the House of Commons and also by the European Parliament."