Plaid Cymru remains a well-kept secret and irrelevant to many Welsh youngsters, one of the party's assembly members has claimed.
Writing on the Nation.Cymru website, backbencher Neil McEvoy said Plaid should end co-operation with Labour, accusing it of working to "meekly" influence the governing party.
Plaid AMs' votes in the Senedd have been supporting Welsh ministers.
The party said it was "always open to discussing and debating ideas".
Mr McEvoy, AM for South Wales Central, said Plaid is a "well-kept secret" in "too many areas of Wales" - he said the party's 14 lost deposits at the June general election "tell us that".
Demanding that the party should "light up the national imagination", Mr McEvoy said that instead of "meekly seeking to 'influence' Labour to implement Plaid manifesto ideas, which is our current trajectory, we should embrace full-on opposition".
"I want to see the Plaid group in the assembly supporting what is right, but opposing with every ounce of our energy what is wrong," he said.
Mr McEvoy called for the party to stop asking "'would the first minister agree...' questions", and called for Plaid to "bin" the "cosy" pairing system - where opposition AMs agree to pair themselves with government AMs when members are unable to attend due to illness or other reasons.
Mr McEvoy described pairing as giving "prior agreement on how many votes the government will win by".
He wrote that Plaid should be a "social movement, not just a political party isolated in the Bay Bubble".
"We should loudly stand for a fully self-governing and sovereign Wales at every given opportunity," he wrote.
"The national Welsh project must be our centre of gravity," Mr McEvoy said, arguing that Plaid "must stand for a reversal of the centuries old trend of young people having to leave Wales to seek their fortune."
Asked later by BBC Wales if Ms Wood had his "concrete support" as leader, he replied: "Of course she does, Leanne is going to be our leader into the next assembly elections.
"What we need to do is get the politics right.
"It doesn't matter who's leader, if we're not going in the right direction we're not going to be successful.
"So with Leanne, I'd like to see a slight change of direction and a policy of no deals whatsoever with Labour."
In August, Mid and West Wales Plaid Cymru AM Simon Thomas said the party needed to "raise its game" in the assembly.
'Unity and determination'
Mr McEvoy was re-admitted to the party group following a short suspension earlier this year after a tribunal ruled a comment to a council officer amounted to "bullying behaviour".
He is still facing an internal party investigation.
A Plaid Cymru spokesman said: "As a democratic movement, Plaid Cymru is always open to discussing and debating ideas.
"We will continue working to realise our vision with unity and determination under Leanne Wood's strong leadership."