UK 1 August 2017 Will Article 127 prevent a hard Brexit? Remainers argue that under international law, MPs must vote on whether to end the UK's single market membership. Getty Images. Sign UpGet the New Statesman's Morning Call email. Sign-up The Conservatives' election failure has made a "soft Brexit" more likely - but it is far from inevitable. The Tories remain committed to leaving the single market (most likely after a lengthy transition period), while Labour has refused to back membership (and intermittently flirts with withdrawal). But for Remainers, hope lies in the little-known Article 127. This section of the European Economic Area (EEA) Agreement (which includes the 28 EU countries, Norway, Lichtenstein and Iceland) states that members may leave provided they give "at least twelve months' notice in writing to the other Contracting Parties". In order to withdraw from the single market, Remainers argue, MPs must vote to repeal Article 127 (as in the case of Article 50). "We haven't triggered EEA exit and won't get through parliament if we try," tweeted James Chapman, a former aide to George Osborne and David Davis. Only six Tory rebels would be required to eradicate the government's working majority of 12. In February of this year, Adrian Yalland and Peter Wilding of the Single Market Justice campaign sought a judicial review of the issue. The application was rejected as "premature" since ministers had not decided which legal route they would to take to exit the EEA - but this does not preclude future challenges. "Philip Hammond knows this," a source said of the Chancellor, who backs a three-year transition period involving continued EEA membership. The campaign argues that the 2015 EU Referendum Bill gave the government no "constitutional right" to leave the single market and that doing so would "violate [the UK's] obligations under international law and unlawfully and unconstitutionally prevent UK citizens from exercising the rights and enjoying the freedoms which the EEA Treaty gives them". The government's position is that no Article 127 vote is required to leave the single market. A No.10 aide told me: "We are only party to the EEA agreement in our capacity as an EU member state. Once we leave, it will automatically cease to apply." This view is supported by Kenneth Armstrong, Professor of European Law and the Director of the Centre for European Legal Studies at the University of Cambridge, who said: "The UK’s obligations under the EEA agreement may not lapse when the UK leaves the EU. But the UK only has limited obligations arising under that agreement. For all aspects relating to customs and compliance with the Single Market rules, it is the EU, not the UK, that exercises rights and duties under the agreement." As well as arguing that the government has no legal right to leave the single market, Remainers contend that they have no mandate. The issue of single market membership, they point out, was not on the ballot paper on 23 June 2016. To which Leavers reply that while the referendum question was formally on EU membership, the Leave campaign backed single market withdrawal in order to end free movement, significant budget contributions and the supremacy of EU law. But as Philip Hammond likes to remark, the electorate "did not vote to become poorer". The problem is not simply that some politicians want to "have their cake and eat it" - but that the public do too. › X-ray decks: the lost bone music of the Soviet Union George Eaton is senior online editor of the New Statesman. Subscribe For daily analysis & more political coverage from Westminster and beyond subscribe for just £1 per month!