WHEN representatives of the Commonwealth’s 53 countries meet in London and at Windsor Castle next week, an array of rosy statistics will be bandied about. The organisation embraces a third of the world’s people, a quarter of the UN’s membership and a fifth of the global land mass. Most of its members share the same legal system and talk the same lingo. It promotes an undefined set of “Commonwealth values”, including democracy and human rights. According to its current secretary-general, Lady (Patricia) Scotland, a dual citizen of Britain and the Caribbean island of Dominica, its hotch-potch of members even share the same sense of humour, born perhaps of their common heritage under British imperial rule. Yet sceptical voices asking what it’s all for have been getting louder.

The answer, in the words of Lord (David) Howell, a British former minister who has long sought to pep up the outfit, is the “cross-pollination of links, ties, alliances and attitudes which together form a latticework of connections unmatched by any other world institution or network.” Its diplomacy helped end apartheid in South Africa and bring independence to Zimbabwe (now hoping to return to the fold, after Robert Mugabe flounced out before being ejected in 2003).

It strives to spur economic development. Arguably it nudged along the UN’s climate-change agreement in Paris in 2015. Thirty-one of its members are deemed “small states” (defined as having fewer than 1.5m people, or having “the characteristics of small states”, thus including Namibia, Papua New Guinea and Jamaica). Most of these tiddlers are islands, some tiny, whose governments enjoy a rare platform offered by the Commonwealth for voicing their environmental worries, especially over climate change.

Though its secretariat is in the conquering Duke of Marlborough’s old mansion in London, it has shed its post-imperial reputation as a white man’s club with Britain, Canada, Australia and New Zealand at its core. But as it has grown, it has been accused of becoming a lacklustre if amiable clutch of freeloaders, driven by nostalgia and by a reverence for Britain’s 91-year-old Queen Elizabeth. It is uncertain whether Prince Charles, her heir, will step into her shoes as titular head of the show. This month he opened the Commonwealth games in Australia, stopping off in Vanuatu, another member country.

Recently, Commonwealth devotees have tried to persuade India to play a bigger part, even by “decentralising” the secretariat to hubs in Delhi and in Accra, Ghana’s capital. But India’s prime ministers have shown faint interest, failing to grace the last three Commonwealth Heads of Government Meetings (CHOGMs, pronounced Choggums), which take place every two years, the last one in Malta. This time, however, Narendra Modi is expected.

The Commonwealth’s plainest drawbacks are that it is short of cash and has no enforcement mechanism bar expulsion. It has been feeble on human rights, laments Maja Daruwala of the Commonwealth Human Rights Initiative, a lobby based partly in Delhi, yet “it’s about human rights or it’s about nothing at all.” In vain did her group oppose letting in Rwanda in 2009. “The status and role of the Commonwealth are somewhat grim,” says Yash Ghai, a veteran Kenyan constitutional expert who has advised several Commonwealth governments. “For people of my generation, that’s a pity. For the younger generation, it has little meaning.”

Keen Brexiteers have long hailed the Commonwealth as an alternative to the European Union, most hopefully as a would-be trading bloc, at a time when Europe has been growing a lot more slowly than countries in the Commonwealth. But a glance at the statistics shows that trade with the Commonwealth is small in comparison (see chart). Whereas the EU accounts for nearly half of Britain’s trade, the Commonwealth accounts for just a tenth. And its share has been slightly falling.

India, Britain’s biggest potential trade partner within the Commonwealth, is widely considered the trickiest with which to do a deal. A loosening of entry visas for Indians into Britain, one precondition, would be anathema to most Brexiteers. Australia, which anyway looks most eagerly to China’s market, and Canada have been negotiating free-trade deals with India for years, so far in vain.

A senior Australian diplomat is blunt: the Commonwealth has “no capacity on trade. We see it as a useful adjunct to our engagement with small island nations but give it no priority.”