Official figures are tipped to show that the UK economy slowed sharply over the past three months and may even have gone into reverse.
Earlier forecasts of 0.5% growth in GDP have now been trimmed back by most City economists to about 0.1% or 0.2%.
A number are even more bearish and predict the figures from the Office for National Statistics could show the economy contracted over the three months to June.
The figure is subject to revision, but a poor reading would heap more pressure on Chancellor George Osborne to come up with an alternative strategy to the Government's deficit reduction plan.
As well as reducing spending, the strategy relies upon the economy growing, but manufacturing, services and construction may be too weak to cope with the fiscal squeeze, say economists.
Manufacturing output rose by 1.8% between April and May but has still "shifted down a gear recently", say observers, with output over the past three months lower than the previous quarter. The services sector, which accounts for some three-quarters of the economy, grew at 0.5% over the past three months, down from 0.8% in the previous quarter.
Shadow chancellor Ed Balls accused Mr Osborne of leading the country into a "Greek-style" trap through cutting back too quickly, adding that unless you have got "people in work paying taxes, the economy growing", it is hard to get deficits down.
TUC general secretary Brendan Barber said: "The Government told us that spending cuts would help the economy grow. Now we know that the opposite is true.
"Whatever today's GDP figures show, we know that the economy at best is stagnant, and that most people are suffering a personal recession as their income fails to keep up the cost of living.
"Even in its own terms, the Government's strategy is not working. The Government had to borrow more in June this year (£14 billion) than it did last June (£13.6 billion). If growth continues to be below what the Government expects, borrowing can only go up."