The High Court is due to deliver a judgement on Wednesday that may affect 85,000 people who lost all or part of their company pensions.
Four people who lost all or part of their company pensions have won their High Court case against the government.
The court has heard claims that the government acted unlawfully by rejecting the Parliamentary Ombudsman's report into collapsed pension schemes.
The Court ruled that the government was wrong to reject the Parliamentary Ombudsman's report into collapsed pension schemes.
The Ombudsman, Ann Abraham, said last year that the government was guilty of maladministration.
The Ombudsman, Ann Abraham, said last year that the government was guilty of maladministration.
But the government has denied this and refuses to pay extra compensation.
The Court decision does not mean that the government must compensate an estimated 85,000 people for their loss.
The court case of four of the pensioners - a judicial review - is an attempt to compel the government to abide by the Ombudsman's rulings.
However, the ruling will intensify pressure on the government over the compensation issue.
The court is due to give its judgement anytime from 0930 GMT.
The case affects 85,000 people who lost their pensions between 1997 and 2005.
Ombudsman's report
Ann Abraham published her report in March 2006.
THE LOST PENSIONS 85,000 people were affected 400 schemes closed with deficitsThey were shut between 1997 and 2005Only limited compensation is available from the Financial Assistance SchemeThe Pension Protection Fund only covers schemes from April 2005 Why we are going to the High Court
She said that the government's maladministration had "caused injustice to a large number of people who, as a result, lost the opportunity to make informed choices about their future".
Specifically, information published in government leaflets had misled large numbers of pensioners into believing their accrued pension entitlements were secure when in fact they were not, the report found.
Several times since then, Tony Blair and his ministers have rejected the idea that the pensioners should be offered full compensation for the pensions they may have lost.
This happened when their employers went bust, or closed their under-funded pension schemes, between 1997 and 2005.
The government has repeatedly argued that it was not at fault because there was no clear link between the information it published and the losses actually suffered by the claimants.
Furthermore, it has argued that it would be too expensive to pay full compensation, which it claims would amount to about £15bn over the next 60 years.
Judicial review
The pensioners have won the support of the Public Administration Select Committee of MPs, which last year urged the government to pay more compensation, and also avoid a constitutional crisis over the authority of the Ombudsman's report.
Ann Abraham said the government was guilty of maladministration
The people whose cases were scrutinised by the Ombudsman are only eligible to make a claim for compensation from the limited Financial Assistance Scheme (FAS).
Their losses pre-date the establishment of the more generous Pension Protection Fund.
But so far the FAS has only paid money to 871 people, with a six month backlog of claims still being assessed.
In January this year the European Court of Justice said that the UK government's pension protection regime was "inadequate", but referred the issue of any further compensation back to the UK's High Court.
At the judicial review hearing at the High Court, the four claimants argued that the government was legally obliged to accept that their pensions should be restored from public money.
A lawyer for the four men who brought the case - Andrew Parr, Rob Duncan, Henry Bradley and Thomas Waugh - argued that the findings of the ombudsman were binding.
She said that "no reasonable public body" was entitled to depart from the findings of the ombudsman.
