But with Britain’s vote in June to leave the European Union, a decision known as Brexit, there is a strong move in the Conservative Party to bring back the glory of empire — and the royal yacht.

“I think we have to ask ourselves what sort of Britain we want to live in and what we can do,” Jake Berry, a lawmaker, said Tuesday in Parliament, “to make Britain great again.” His answer? “If Brexit is going to mean successful Brexit, it should also mean the return of our royal yacht!”

The Conservative benches loudly murmured their approval, and about 100 Tory lawmakers supported the motion — roughly the same number who fiercely backed Brexit before the referendum, giving former Prime Minister David Cameron fits.

Many of them have dreams of a wholly sovereign Britain with all the old symbols of this island nation’s empire, when “Britannia ruled the waves” — the royal yacht, the old dark blue British passport, the supreme power of Parliament. And even though the Brexit supporters won, they remain combative, suspicious that Mr. Cameron’s successor, Theresa May, who quietly opposed Brexit, will somehow betray them. And they have no intention of giving up in their desire for a clear break with Brussels.

With the same small majority in Parliament, Mrs. May is thus as vulnerable to intraparty parliamentary pressure as Mr. Cameron was. If the vote was meant to “reclaim” full British and parliamentary sovereignty from those supposedly faceless Brussels bureaucrats, then, these same lawmakers argue, Mrs. May should consult them on every aspect of Britain’s negotiating position with the European Union.