Most people's complaints were about problems with the benefits system but the Child Support Agency (CSA) also came in for heavy criticism.

What does the Ombudsman do?

He deals with complaints from people who believe that they have suffered an injustice because of maladministration by government departments, agencies, and other public bodies

As a whole, the department accounted for more than half of the total number of investigations launched by the Parliamentary Ombudsman.

The Ombudsman, Sir Michael Buckley, said the Benefits Agency (BA) had failed to handle a number of claims for disability or incapacity related benefits "at all well".

And he said there were continuing problems with some of the Child Support Agency's (CSA) enforcement procedures.

Compensation payment

In one case, a five year delay and mishandling by the CSA could have contributed to the repossession of a couple's home.

Complaints down

Overall DWP complaints down from 720 last year to 693

The CSA was ordered to pay �26,931 compensation to the couple, including an ex gratia payment of �15,000 and a further �1,000 to "demonstrate the CSA's regret" for the time taken to conclude the case.

Sir Michael said: "While there could be no certainty that in the absence of maladministration [they] would have been able to retain their home, the Ombudsman found that they would certainly have had a better chance of doing so."

This was one of 187 complaints against the CSA.

"Regrettably a considerable number of complaints against CSA continue to show that CSA have failed to enforce payment from a non-resident parent in an effective and timely way," Sir Michael said.

Medical assessments

A number of other cases identified in the report concerned claims for disability - or incapacity related benefits.

These "were not handled at all well by BA", said the Ombudsman.

In particular, the report identified problems with medical assessments for benefit claimants.

In April, the Commons' Public Accounts Committee slammed the system and said it was failing up to 130,000 vulnerable people a year.

The system is contracted out to SEMA, a private company, but is overseen by the DWP.

The Ombudsman said he was still receiving complaints highlighting "inappropriate" conduct by doctors who assessed claims.

Tax problems

The Inland Revenue was another department that generated complaints - although at 206 the figure was slightly lower than the previous year.

In one case the Revenue took an "extraordinarily long time" to deal with a complex capital gains tax issue, which had so far taken five and a half years to resolve.

Following the Ombudsman's intervention, the Revenue apologised; waived some �42,000 of interest; and offered to make a consolatory payment and meet reasonable costs arising from the mishandling.

In another case, an accountant complained that clients had received penalty warning notices, even though their end of year returns had been correctly submitted.

He was even more frustrated so when the Revenue's letter of apology showed an incorrect address, the Ombudsman said.