Over three-quarters of the 800 delegates voted to support Horwath in the leadership review, which is automatic after an election.
Horwath was approved by 76.4 per cent of delegates.
NDP house leader Gilles Bisson says New Democrats are thrilled with Horwath's leadership after they increased their seat count last October in their best election showing in decades.
Horwath's leadership is also being tested by union leaders and delegates who deferred a resolution seeking approval of her handling of budget negotiations with the minority Liberal government.
Ontario Federation of Labour president Sid Ryan says the Liberals' are attempting to destroy the collective bargaining process by threatening to impose a wage freeze on the public sector.
Ryan says Horwath should call Premier Dalton McGuinty's bluff and refuse to compromise on the legislated wage freeze.
He says if that triggers another election, it'll be on McGuinty's head, not Horwath's.
The Conservatives have vowed to vote against the budget, so the Liberals need NDP support or the minority government will be defeated, triggering an election.
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