As U.K. Prime Minister Theresa May's proposed Brexit deal continues to face a pummeling in Parliament, the only option is to return the matter to the British public for a second referendum, according to Drew Hendry, a U.K. member of parliament from Scotland. Hendry on Wednesday joined the chorus of parliamentarians calling for more time before Britain's looming departure from the European Union. "There needs to be a situation now where there's an extension to Article 50 to allow this to go back to the people," Hendry told CNBC's "Squawk Box" Wednesday. Article 50 refers to the formal two-year process governing the U.K.'s departure from the European Union. "The reason for that is very clear: There is a constitutional crisis now in the U.K. Theresa May's government is now feral," added Hendry, a Scottish National Party politician. U.K. lawmakers rejected on Wednesday the prospect of leaving the EU without a deal. On Thursday, they will vote on whether to seek an extension to Article 50, which could prolong its exit deadline. Such an extension would need to be granted by all 27 other member states of the EU.

Pro-Brexit protesters demonstrate outside the Houses of Parliament on March 13, 2019 in London, England. Dan Kitwood | Getty Images

If the extension goes ahead, that could open up the possibility of a second Brexit referendum, a prospect that worries Brexit supporters. However, Hendry said it was necessary to guarantee the best outcome — especially for Scots, who he said would be "disproportionately affected" by Brexit. Scotland voted to remain in the EU by a majority of 62 percent. "All of the versions of Brexit bring deep economic harm in their wake to our people, and that disproportionately affects Scotland," said Hendry. "The only outcome that makes any sense now is to go back to the European Union ... and say that we need a delay now so that we can take this back to the public, they can vote on whether or not to remain or accept this shoddy deal that doesn't work." That second referendum should include a "remain" option, Hendry added.

A second Scottish referendum?