“Britain is leaving the European Union and there can be no turning back,” declared Prime Minister Theresa May earlier this month as she announced a surprise snap election. Holding the election would, she insisted, help unify Westminster behind her before detailed negotiations with the EU begin.

With a comfortable lead in the June 8 polls, she has reasons for optimism. However, could some tactical voting initiatives derail those prospects? Hopes are growing as a couple of such plans have emerged since the announcement of the general election, aimed at preventing a hard Brexit of the kind envisaged by Ms. May’s government (exiting the single market and an end to free movement).

On Wednesday, Gina Miller, the investor who took the government to the Supreme Court to ensure it had to get parliamentary nod before triggering Brexit, launched a campaign, ‘Best for Britain’. It will support candidates from across the political spectrum, including the Conservatives, who would fight to give Parliament a “meaningful vote” on Britain’s future relationship with Europe, and would be “prepared to reject anything which would make Britain worse off”.

The campaign has raised over £3,00,000 through a crowdfunding initiative and will use polling data (from the referendum and the most recent general election) and other information to identify how supporters’ votes could make the biggest difference, as well as using technology to spread the message. “Only tactical voting in this election can ensure that Parliament plays its full part in the future of this country,” Ms. Miller says.

The trouble for champions of tactical voting will be the strength of support for the Conservatives, who have been winning over voters from the U.K. Independence Party

A separate initiative, by several grass-roots movements, including ‘Open Britain’, has identified a list of parliamentary seats that will be targeted, as part of efforts to unseat some of the MPs who have been most vocal in their endorsement of the government’s version of Brexit. Yet another by Ben Goldacre, author of the best-selling book, Bad Science, was launched on social media, more focussed on reducing the size of the likely Conservative majority, rather than Brexit.

Mixed results

Tactical voting is not a new phenomenon in Britain, where the first-past-the-post electoral system means that the winning candidate can hold considerably less than half the vote in their constituency and it has been tried in many elections before with mixed results. There is some evidence of its success in 1997, when the Labour party under Tony Blair ousted the Conservatives, but that was when the Conservatives were polling at just over 30%, says John Curtice, Professor of Politics at Strathclyde University and a noted pollster.

“Tactical voting happens when voters hate one party that is likely to win and are indifferent between two or more other parties but such voters tend to be relatively rare,” he says. Could the issue of Brexit change that? The Labour has supported the triggering of Article 50, though a number of MPs opposed it, leaving the Liberal Democrats, with just nine sitting MPs, as the main opponent of Brexit.

The trouble for champions of tactical voting will be, he says, the strength of support for the Conservatives, who have been winning over voters from the U.K. Independence Party, and in some seats are likely to have over 50% of the vote. “Tactical voting can do nothing there,” he says, adding that it was only likely to make a difference when small single-digit percentages were involved.

However, it’s unlikely to deter the supporters of the tactical voting initiatives, as many remain hopeful that a hard Brexit of the kind being pushed by the Prime Minister is far from a done deal.

Vidya Ram writes for The Hindu and is based in London