Britain's longest double-dip recession for more than 50 years will be confirmed in official figures.
Gross domestic product (GDP) - a broad measure for the total economy - is forecast to have shrunk by around 0.2% between April and June in its third quarter in a row of contraction.
That would mark the longest double-dip recession since quarterly records began in 1955 and is believed to be the worst since the Second World War.
The last double-dip recession was in the 1970s, when the economy was hamstrung amid soaring oil prices and a miners' strike, but that only lasted two quarters.
The latest decline is set to have been worsened by the extra bank holiday surrounding the Queen's Diamond Jubilee and record rainfall in April and June. Recent estimates from the Bank of England said the celebrations could wipe up to 0.5% from output, while its governor Sir Mervyn King has warned the special events including the Jubilee and the Olympics will skew figures this year.
The figures from the Office for National Statistics (ONS) will be a preliminary estimate and be subject to revision.
The economy entered a technical recession in the first quarter of the year, with GDP declining 0.3%, following a 0.4% drop in the final quarter of 2011. This followed its five quarters in a row of falls in 2008 and 2009 from which the economy has not fully recovered.
Investec chief economist Philip Shaw, who predicts a 0.4% fall in GDP, said the figures for the construction sector may be a "disaster", with falls of as much as 6% between April and June, following a 4.9% drop in the first three months of 2012. The powerhouse services sector - which makes up some three-quarters of the total economy - is also on course to deliver a disappointing result following a series of weak surveys suggesting retailers failed to get a significant uplift from the Jubilee.
Yet the ONS's figures have been called into question in recent months because they are at odds with more upbeat industry surveys and improving employment figures. Some economists have even suggested that the UK may not be back in recession at all and have voiced fears that gloomy official figures may be hitting confidence.
However, the ONS's figures are expected to show a return to growth in the current quarter, partly driven by the London Olympics. But the recovery is set to be lacklustre for months to come, with the International Monetary Fund having recently revised down the UK's growth forecast to just 0.2% in 2012, compared with its previous estimate of 0.8%. And it expects growth of just 1.4% in 2013, which is much weaker than historical averages.