How much do you have to be earning to lose your child benefit?

Under the new legislation families with one parent earning more than £50,000 will lose part of their child benefit. If one parent earns more than £60,000 their child benefit will be withdrawn altogether.

What these families will actually be losing is £20.30 a week paid for the first child and £13.40 a week for every child after that until the age of 16 or 18, if they are still full time education, in some cases this may continue until the child is 20.

How much does the government hope to save with this new benefit scheme?

Approximately £1.5bn a year, which will be used to help reduce the deficit.

What are critics of the changes saying?

Critics have pointed out that two parents earning £49,000 a year will keep their benefit, while a family with one parent working who earns £51,000 will lose their benefit even though jointly they have a smaller household income.

They also point out that those who never opted out of child benefit by the deadline will now have to fill out a self assessment tax form creating complexity in the system.

If someone or their partner keeps claiming child benefit when now not entitled to it the money will have to be clawed back by High Income Child Benefit Charge run by the HMRC after the recipient declares it in a self assessment tax form.

The Institute of Fiscal Studies (IFS) estimates that 500,000 extra people might have to fill in these forms as a result of the change.

How many people will be affected by the cuts?

It is estimated that more than a million will be affected by the changes with the IFS estimating people could lose about £1,300 a year.

What has the treasury said?

A Treasury spokesman told the BBC: "Withdrawing child benefit on the basis of the combined family income would require intrusive means-testing of all eight million households getting child benefit. The way we are doing it is simpler for the vast majority of families."