John Brown says he is starving himself in protest at the CSA

John Brown, 56, of Newbury, Berkshire, says he has survived on two glasses of wine and soya milk for eight weeks, in protest at a demand for �22,000.

But former partner Ann says she has struggled to afford school lunch money for their 17-year-old daughter.

She told BBC News Online: "I have given them a new name - Fathers 4 Injustice."

My daughter is a feisty 17-year-old who gets angry with injustice and she sees this as a huge injustice Ann, ex-partner

The 56-year-old from south London, who wants to stay anonymous to protect her daughter, added: "What do Fathers 4 Justice think doing by interfering in the justice that my daughter is entitled to?

"This hunger strike is a red herring, a smoke screen."

The couple, who met through a mutual friend, split acrimoniously in 1996 and Mr Brown has not seen his daughter since she was 12.

"My daughter is a feisty 17-year-old who gets angry with injustice and she sees this as a huge injustice.

"But the real villian of the piece here is the Child Support Agency for failing to collect."

F4J is acting as a catalyst to get this case cleared up Mike Ellis, Fathers 4 Justice

Ann says her former partner began his hunger strike after he was ordered to disclose his finances to the CSA.

He has already lost two appeals over �11,000 of the �22,000 the Agency is demanding, dating back seven years.

Mr Brown says the stress of the case has forced him to abandon his career as an advertising photographer.

He says the CSA has massively overestimated his income and has threatened to step up his hunger strike to a water-only fast if it is not resolved.

Mike Ellis, Thames Valley area Fathers 4 Justice organiser, said: "Fathers 4 Justice represents fathers who want to take part in their children's lives and withholding payments is not part of that.

"F4J is giving Mr Brown moral support and acting as a catalyst to get this case cleared up."

A spokeswoman from the CSA said the agency could not comment on individual cases.