Article 50 of the EU's Lisbon Treaty that deals with the mechanism for departure is pictured near an EU flag following Britain's referendum results to leave the European Union, in this photo illustration taken in Brussels, Belgium, June 24, 2016. REUTERS/Francois Lenoir/Illustration/Files

LONDON (Reuters) - The British government expects to lose its legal battle to start the Brexit process without going through parliament, and has drafted versions of a bill to put to lawmakers after the ruling, the Guardian newspaper reported on Tuesday.

The Supreme Court is expected to rule in the next two weeks on whether the government can trigger Article 50 of the European Union’s Lisbon Treaty, the first formal step toward leaving the bloc, without first getting parliament’s approval.

Citing unnamed sources, the Guardian reported that ministers had privately conceded they were very likely to lose the case, and had drawn up at least two versions of a bill to be presented to parliament after the ruling. [bit.ly/2iiL6oP]

The report also said the government had asked the court for early sight of the ruling before it is made public, to allow for contingency planning.

During the Supreme Court hearing in December, government lawyer James Eadie said that if judges ruled parliament had to give its assent to the triggering of Article 50, the solution would be a “one-line” bill.

The Guardian said ministers were hoping the ruling would allow Prime Minister Theresa May to put forward a short bill or motion, narrowly focused on Article 50, to make it difficult for lawmakers to amend.

Those in favor of a clean break with the European Union are concerned that parliament, where a majority of members were in favor of remaining in the bloc, could seek to water down ministers’ plan in pursuit of a so-called “soft Brexit”.

The government’s opponents in the legal battle argued that triggering Article 50 would nullify the 1972 act of parliament that opened the way for Britain to join the EU, and therefore parliament had to give its assent for its act to be undone.

London’s High Court backed that argument, prompting the government to appeal to the Supreme Court, Britain’s highest judicial body, in December.