The Overseas Electors Bill is due for a second reading in the House of Commons on February 23.
But if there was another referendum on Brexit, expats are not guaranteed a vote.
The UK Foreign Office told the Olive Press: “There is no one rule for who can vote in a referendum.
“When a national referendum is announced, Parliament will decide who can vote in it as part of the legislation on that referendum.”
Some 17,410,742 Brits voted to leave the EU in the June 2016 vote, compared to 16,141,241 who opted to remain.
Around 800,000 expats believed to be living in Europe were forbidden from voting, although the figure could be much higher.