He told the party's spring conference in Llanelli there was a "palpable" appetite to bring 17 years of Labour-led government to an end.

Plaid Cymru had "ambitious but achievable" ideas to boost health, education and the economy, he said.

"Wales needs a break, a long break. Labour needs a break," he added.

"Our ambition for Wales can appeal to all," Mr ap Iorwerth said.

"Regardless of people's background, circumstances, or previous loyalties, the whole nation can unite behind our programme for a well, well-educated and wealthier Wales.

"Real change is on the ballot paper at this election. Now is the time to decide."

Adam Price, the former MP now standing for the assembly, predicted Labour would lose the election.

"They deserve to lose because they have already lost any sense of direction, any scrap of creativity, of vision, of drive," he said.

Plaid Cymru is currently the assembly's third largest party with 11 of its 60 seats, but it holds no constituency seats outside of mid, west and north west Wales.

It was part of a coalition government with Labour from 2007 to 2011.