A majority of U.K. lawmakers think that remaining in the European Union’s single market is compatible with honoring the Brexit referendum result, according to a survey of members of parliament.

The poll commissioned by the U.K. in a Changing Europe showed that 56 percent of lawmakers said it was possible to consider Britain “had really left the EU” and delivered on the referendum even if the country stayed in the single market. That’s down from 66 percent a year earlier.

Among Conservative lawmakers the figure is just 23 percent, down from 50 percent a year ago, while Labour lawmakers have become more convinced of the benefits of the world’s largest trading bloc. Ninety percent of Labour members of parliament think it’s possible to reconcile remaining in the EU’s internal market with Brexit, which is up from 86 percent a year earlier.

Prime Minister Theresa May has said she will pull the U.K. out of the single market, since to stay in would mean accepting freedom of movement, the jurisdiction of European judges and large budget payments. But her Cabinet, which remains split on the issue, has yet to decide exactly what kind of future relationship it will seek with the EU. Leaving the single market will hit the service industries that dominate the U.K. economy particularly hard.

The research was conducted by Ipsos MORI in November and December 2017 on behalf of The U.K. in a Changing Europe and the Mile End Institute at Queen Mary University of London. Interviews were conducted face-to-face with 105 lawmakers.