Households at every income level have seen their living standards fall since the last election, according to independent figures that put pressure on George Osborne to translate economic growth into higher incomes.

According to data from the Institute for Fiscal Studies, households at the top and bottom of the income scale are worst affected, but middle-income earners who pay the 40p tax rate suffer most when their wages increase.

As the chancellor puts the finishing touches to his Budget, the findings will add to the clamour from Tory backbenchers for a rise in the 40p threshold to exclude more middle-income families who are dragged into the higher rate tax band as their salaries rise.

New figures from the IFS's "green budget", a scene-setter for the chancellor's statement, reveal that stagnant wages, rising shop prices and austerity measures have hit the real incomes of all workers across the pay spectrum, supporting Labour's claims that all workers are worse off since 2010.

The detailed analysis contrasts with a study by Treasury officials, published on Tuesday, that found a majority of workers saw a boost to their real incomes in all but one of the last seven years.

The Treasury said full-time workers in steady employment had enjoyed rising wages after taking inflation into account since 2006, with the exception of 2011.

A spokesman said it wanted to dispel concerns that the slow growth in average weekly earnings was "evidence that people aren't benefiting from improvements in the labour market".

He said: "Relatively strong performance in employment naturally has implications for movements in average wages. Strong employment growth can result in a compositional change in the labour market, in part reflected through new entrants to employment. This will have an effect on average wage growth.

"To examine this we need to look at wage growth after removing the influence of the changes in composition of the labour market."

However, the study excluded almost half the workforce, many of them in key groups that have suffered wage cuts.

More than 10 million people who moved jobs or entered the jobs market were not counted alongside the 3.7 million self-employed people. The estimated one million people on zero hour contracts were also excluded, along with any tax and benefit changes.

Labour said the Treasury was "desperately trying to tell people facing a cost-of-living crisis they've never had it so good".

It added: "In fact the latest figures show that under David Cameron real wages have fallen by over £1,600 a year. And IFS figures show families are on average £891 worse off this year due to tax and benefit changes since 2010. This analysis is totally out of touch with the real world. It ignores the one-third of full-time workers who have not stayed in continuous employment and the 27% who work parttime."

Much of the debate over living standards has focused on the highest and lowest paid. The IFS, which unlike the Treasury includes all tax and benefit changes in its calculations, said last month that headline figures showed that workers at the top and bottom suffered the most. Since 2010 the incomes of households at the bottom of the income range saw a drop of 5.1% while those at the top suffered a 4.3% drop.

Further analysis shows that middle income earners below the 40p tax threshold were only 1.7% worse off, but were more than 3% worse off once they began to pay the higher rate. Last year's cut in child benefit for higher rate taxpayers also ate into incomes alongside a slide in wage rises, which slipped below 1% in the second half of 2013 while inflation remained above 2%.

The IFS said living standards would begin to rise later this year but a strong recovery over the next few years was unlikely. According to the Office for Budget Responsibility, the government's independent forecaster, real earnings are not expected to return to their 2009–10 levels until 2018–19.

"Further discretionary cuts to benefits and tax credits will put downward pressure on real incomes, particularly for low-income households. Given this, it seems highly unlikely that living standards will recover their pre-crisis levels by 2015–16," it said.