Italian Prime Minister Matteo Renzi says he expects a constitutional referendum being put to voters next month to pass, but says he will "verify the political situation," if it fails.

Renzi has for months been trying to backtrack on a statement staking his political future on the success of the Dec. 4 referendum.

But opposition politicians have taken him up on the challenge and are vowing to press for a new government if voters reject the proposed changes to the country's lawmaking system.

Polls suggest the results will be close.

Renzi told a press conference in Rome on Friday that his government was founded on the pledge to reform institutions "and I think in the deep heart of the country there is an extraordinary desire to change."