Nick Clegg will today appeal for frustrated Liberal Democrat activists to "move on" from damaging rows over the NHS and tuition fees.
The Deputy Prime Minister insisted there could be "no more looking back" and party members should be "shouting our achievements from the rooftops".
The exhortation comes as the Lib Dems kick off what could be another fractious spring conference in Gateshead.
Last year's event was dominated by dissent over the coalition's controversial health shake-up.
The legislation was "paused" as a result of the outcry and opposition from NHS workers, and has since been amended more than a thousand times.
But it is not yet clear whether the Government has done enough to placate the Lib Dem grass roots.
The conference is expected to vote to consider a topical motion on the NHS on Sunday, which could prove embarrassing for Mr Clegg.
Speaking at a rally in Gateshead this evening, the party leader will say he has never "ducked fights".
"We've made some difficult decisions, not all of them popular," he is to say.
"But we made all of them with only one test in mind: What was the right thing to do for the country?
"And now it is time to move on. To stop justifying being in Government and start advertising being in Government.
"To stop lamenting what might have been and start celebrating what is. To stop defending our decisions and start shouting our achievements from the rooftops.
"We're in Government, and it is a better Government for it. Fairer, freer and greener.
"Lower taxes for working people. Fairer chances for our children. And the beginnings of a new, green economy that benefits everyone in every city, not just a few in the City of London.
"So: no more looking back. You can't drive if you're only looking in the rear-view mirror.
"We have to look forwards, to the better future that we are building for our children.
"So let's tear off that rear view mirror and look straight ahead. Let's get on with the job that we all came into politics to do. Making this a more liberal nation."
Mr Clegg will also be supported by party president Tim Farron - who previously expressed concerns about the health reforms.
"We got three quarters of our manifesto into Government policy, so I hereby allow you to stop saying sorry for the quarter we didn't get," he will say.
"And if people wanted that missing quarter, well they should have flipping voted for us shouldn't they?"