As resources were diverted in the face of public outrage, the agency allowed a new backlog to build up of 77,000 applications for residence from European nationals.

In less than three years, the Ombudsman has received more than 1,300 complaints from MPs. Of those investigated last year, 97% were upheld.

Ms Abraham said: “If the Agency were operating effectively, any application… would be determined within a reasonable period. The Agency’s failure to resolve applications within reasonable timescales can have serious implications for the individuals concerned, and for society in general. There is also a risk for the Agency of a loss of faith in their system by applicants, by other related organisations, and by the public at large.”

She praised the “significant progress” made in reducing the asylum backlog. But she said long delays meant asylum seekers would be hard to remove even if their cases are rejected.

Lin Homer, chief executive of the UK Border Agency, said: “We take the Ombudsman’s recommendations seriously and welcome the assessment that our complaints systems are improving. The UK Border Agency is continuing to make progress in dealing with the legacy backlog of older asylum cases and has already concluded more than 235,000 cases. I am confident we are on course to conclude these cases by the summer of 2011.”

Questioned whether the boys still talk about Goody, who died at her Essex home last year at the age of just 27, he said: “We talk about her in a very normal capacity. Like when they’re cleaning their teeth – Jade was a dental nurse and they’re very aware of that.

“They say things like, ‘Mummy did this, didn’t she?’ or ‘Mummy had one of those cars!’ You can see she’s always on their minds. I’m not expecting them to forget about Jade and I don’t want them to. They’re constantly around people who were close to their mum.”

In an interview with Woman’s Own, Brazier, 30, said it would be “a huge problem” if his children – who are having grief counselling – questioned him if their mother was ever coming back. It would mean they didn’t know that Heaven meant forever and I wouldn’t be doing my job properly,” he said. “As hard as it is to tell your children that, they didn’t need to be told too many times – they understood.

“I’m doing everything I possibly can to protect the children from potential issues that can arise from not dealing with bereavement. I’m working with a charity called Grief Encounter and they’re sending a counsellor to visit Bobby and Freddy on a regular basis. We always make sure we’re talking about it at the right time and in the right way.”

Brazier, who was left full custody of the former couple’s two children when Goody died in March, said the boys will also spend Mother’s Day with his mother Janette, 46, who is helping to raise them.

It would offer a straight choice between the existing system and AV – under which voters would rank candidates in order of preference.

The Liberal Democrats will seek to change the question to offer the choice of a more proportional system – the single transferable vote – instead of AV.

They also want to bring forward the last date of the referendum to May next year and close what they say is a loophole that would allow an incoming Conservative administration to abandon the vote without the need for fresh primary legislation.

Campaigners for voting system change welcomed the AV proposal as a “small step” towards making the electoral system more representative.

Mr Cameron called at the weekend for the “crazy” vote to be dropped and for MPs to delay their half-term holiday by a day to debate Parliamentary reforms proposed by a committee chaired by Labour backbencher Dr Tony Wright to strengthen scrutiny of the government.