With the 200th anniversary this week of the July 11, 1816 purchase through an Act of Parliament of the Parthenon Marbles for the British Museum, members of parliament (MPs) are introducing a bill that would repatriate the ancient artifacts. Greece has advocated for their return ever since the country’s 1832 War of Independence, but with the UK soon to negotiate its departure from the European Union following Brexit, supporters see this as an opportunity to finally send the sculptures back to their home.

The Parthenon Marbles, sometimes called the Elgin Marbles for Lord Elgin, who sold them to the British Museum, have a contentious and complicated history. The complications stem from the circumstances under which they were removed, and whether that removal under a time of Turkish occupation means they should be returned. The “Parthenon Sculptures (Return to Greece) Bill” asks for “provision for the transfer of ownership and return to Greece of the artefacts known as the Parthenon Sculptures, or Elgin Marbles, purchased by Parliament in 1816; to amend the British Museum Act 1963 accordingly; and for connected purposes.”

The Independent reported that the bill was introduced by Liberal Democrat Mark Williams, with support across parties including Labour, Scottish National, and Welsh nationalists. Williams said that in 1816, Parliament “effectively state-sanctioned the improper acquisition of these impressive and important sculptures from Greece.” The Independent also quotes the chair of the British Association for the Reunification of the Parthenon Sculptures, Andrew George, who said that the execution of Brexit could be an ideal time to show that it “doesn’t involve us becoming inward-looking and xenophobic towards the EU, but more confident, more able to be gracious. And there could be no better demonstration of that generosity and graciousness than to do what would be the right thing by the Greeks.”

Prime Minster David Cameron, who once quipped Britain wasn’t going to “lose its marbles,” is about to be replaced by Theresa May, although her stance on the sculptures remains unclear. What is evident is a shifting perception of what repatriating the Parthenon Marbles could mean to the UK’s image. An Ipsos MORI poll recently found that 69% of British people who knew about the marbles were in favor of their return, as opposed to 13% who were against it.

However, the history of recent attempts is not favorable. UNESCO offered to mediate a deal in 2013 and then in 2014, and after shrugging off those requests, the British Museum lent one of the ensemble’s larger statues to the State Hermitage Museum in Russia. In May of last year, the Greek government opted not to go to court for their restitution. Meanwhile this May, Greece’s Minister of Culture and Sports Aristides Baltas told the Guardian that the country is “trying to develop alliances which we hope would eventually lead to an international body like the United Nations to come with us against the British Museum.”

The British Museum, on its website, has a clear “position of the Trustees of the British Museum” that states:

The Museum is a unique resource for the world: the breadth and depth of its collection allows a world-wide public to re-examine cultural identities and explore the complex network of interconnected human cultures. The Trustees lend extensively all over the world and over two million objects from the collection are available to study online. The Parthenon Sculptures are a vital element in this interconnected world collection. They are a part of the world’s shared heritage and transcend political boundaries.

The museum’s new director, Hartwig Fischer, has personally backed this position. The institution points out that not all of the Parthenon Marbles are in London, as the Louvre, Vatican Museums, and other museums have fragments, and “approximately half of what survive from antiquity” are at the Acropolis Museum. The Greek museum near the Parthenon ruins also displays casts of what’s missing.

Yet the most superb parts of the Parthenon Marbles are arguably those at the British Museum, which has the lavish pediment statues and gorgeously carved friezes and metope panels. The poet John Keats, on seeing the pieces in London, was struck by the contrast between their decay and beauty, writing: ” So do these wonders a most dizzy pain, / That mingles Grecian grandeur with the rude / Wasting of old time—with a billowy main— A sun / —a shadow of a magnitude.” Whether the Parthenon Marbles will remain as a centerpiece of the British Museum or be repatriated remains a shadowy question, but one of great magnitude.