One of Wales’ foremost experts on Welsh politics has warned Plaid Cymru’s three leadership contenders that any talk of forming a Welsh Government without Labour’s support is “completely fantastical”.

Writing in Barn magazine, Professor Richard Wyn Jones said that each of the party’s contenders would have to come to some kind of arrangement with Labour if they wanted to be in government.

“In all seriousness, what extra constituencies does Plaid Cymru expect to capture?” he asks. “Even expecting to win over 20 is psychedelically optimistic.

“And even in such a scenario, they could not expect to form a government without a coalition or agreement.

“Since coming to any kind of agreement with the Tories would be impossible, it is unavoidable that this would mean some kind of agreement with Labour.”

Richard Wyn Jones suggested that it could be more likely that Plaid Cymru would convince the Labour party to support independence than lead the country to independence as a majority party.

“Partly because of Plaid Cymru’s influence, Labour has travelled far in terms of policy, for instance in supporting a Welsh legal authority,” he said.

“It’s also true that the experience of the Scottish Independence Referendum in 2014 and Brexit two years afterwards has led to all kinds of discussions within Labour about Wales’ fate within a nation-state that has changed completely.”

Therefore, the questions of the relationship with the Labour party was the largest strategic issue facing the party, he said.

“Perhaps a little fantasy is acceptable within an internal contest, but reality will bite in the end,” he said.

The September issue of Barn is on sale now for £3.99.