With the European Union appearing lukewarm toward U.K. Prime Minister Boris Johnson's latest Brexit proposal, the deadline for Britain to leave the bloc could once again be pushed back, according to a British lawmaker.

The U.K. currently has until Oct. 31 to leave the EU. Britain's departure has been pushed back multiple times from the original March 29 deadline, after British members of parliament thrice rejected former Prime Minister Theresa May's withdrawal agreement.

If the EU doesn't agree to Johnson's proposal, it would have to once again delay the U.K.'s departure to avoid a no-deal Brexit, said Jitesh Gadhia, a member of the House of Lords, the upper chamber of the British parliament.

"If you think about it from the EU perspective and if you look at their choices: Do you seal a deal with Prime Minister Johnson now or do you actually roll the dice on an extension and election hoping that you might have a more favorable counterparty?" Gadhia told CNBC's Tanvir Gill on Friday at the World Economic Forum in New Delhi, India.

He said even though "the omens aren't great" on getting the EU to agree to Johnson's deal, the bloc still appeared to be open to further negotiations.

Within the U.K., a majority of lawmakers want a deal and they have blocked Johnson from taking Britain out of the EU without a deal on Oct. 31. If no deal is in place by Oct. 19, Johnson is bound by law to ask the EU for a delayed departure date.

Another extension would pave the way to a general election in the U.K., according to James Smith, developed markets economist at Dutch bank ING.

"Once an Article 50 extension is secured, the countdown to a general election – perhaps as little as five weeks later – will almost certainly begin," Smith wrote in a Wednesday note.

— CNBC's Holly Ellyatt contributed to this report.