Leanne Wood joins Plaid race with call for independence
Leanne Wood has become the fourth Plaid Cymru AM to enter the race for the party leadership.
She will look for backing when nominations open in the new year.
Ms Wood, an AM since 2003, said she would prioritise the economy in building the case for "real independence" for Wales.
Current party leader Ieuan Wyn Jones announced he would stand down after a disappointing result for Plaid at May's assembly election.
Ms Wood said her campaign will be based on ideas to create jobs and give Welsh people control of the country's natural resources.
She said: "I have always been a campaigner, an activist who became a politician to further those aims and that's why I'm now putting my name forward as leader of the party I have been a proud member for 20 years - all my adult life.
"My first hand experience of recession and its impact during the 1980s gives me a determination to make sure that we do not lose yet another generation to youth unemployment.
"Tackling those economic challenges goes hand in hand with our journey to independence."
An internal review of the party - commissioned after May's election - will spark debates about Plaid's political direction, she said.
"I have a clear vision of what our future direction should be; building the case for real independence," she said.
Plaid had been "less than clear" about what it meant by independence, she added. "Now is the time to change that."
Carmarthen East and Dinefwr MP Jonathan Edwards said: "The key question in this election is which candidate can best expand the appeal of the party?
"Leanne has proven over the years that she is one of the party's leading communicators.
"People connect to Leanne easily, they trust her, and these would place her leadership and the party in a very strong position in these very exciting times for our nation."
Ceredigion AM Elin Jones and Mid and West Wales AM Simon Thomas have said they want to stand. Lord Elis-Thomas, who first led Plaid in the 1980s, has been endorsed by his local party.