Most voters believe the coalition will collapse before the next election, according to a new poll conducted after fresh divisions developed between the Tories and Lib Dems.
Only one in six people expect the parties to still be partners by 2015, and the proportion expecting the partnership to break down within two years has doubled in two weeks.
Some 16% of those who took part in the ICM poll believe the coalition will last until David Cameron goes to the country, down from 33% a fortnight ago.
The number expecting the union to last until a few months before the next election has also fallen from 23% to 19%.
Almost half, 43%, think the coalition will fall apart in the next couple of years - almost double the 23% figure from late July.
Another 11% believe it will end even sooner, up from 7%, giving an overall total of 54% who no longer expect the Government to survive until 2015.
The findings, published in the Guardian, come as David Cameron and Nick Clegg go on holiday with the coalition partnership at a new low after a row over House of Lords reform.
The Deputy Prime Minister announced last week that he would order his MPs to vote against boundary changes in retaliation for Lords reform failing.
Mr Clegg declared that the coalition contract was "broken" because Mr Cameron had failed to win round Tory rebels to ensure the constitutional reform goes ahead.
The leaders met for dinner on Friday to discuss their next steps and work is under way on a mid-term progress report, to be published in September.
This is expected to set out the achievements of the coalition so far and its priorities for the rest of the five-year term, which are likely to focus on boosting the economy.
Mr Cameron is also expected to use his summer holiday to mull over his first reshuffle, which is expected in the coming weeks.
ICM Research interviewed a sample of 2,021 adults from across the UK online on August 8-9 and the results were weighted to reflect the general population.
The results came after two other polls suggested the Olympics had not done much to increase the Government's popularity.
A YouGov poll for the Sunday Times still had Labour on 42%, the Tories on 34% and the Lib Dems and Ukip on 8% each.
An ICM "Wisdom of Crowds" poll for the Sunday Telegraph, which asks how people expect support to be split at the next election, had Labour on 38%, the Tories on 31% and the Lib Dems on 17%.