A man who twice ran away with a 13-year-old girl has been jailed for 30 months by a judge.

But Judge Geoffrey Kamil criticised a legal loophole which means that he could not ban Andrew Roberts, 25, from working with youngsters in the future.

Because Roberts had been charged with simple abduction of the teenager rather than anything under the Sexual Offences Act the judge noted that he could not impose any sort of ban.

Judge Kamil also queried the fact that he could have imposed a ban if the offence had involved a parent, but not abduction by a stranger. "That's something I find very difficult to come to terms with,'' he said.

After passing the jail sentence, Judge Kamil added: "I do intend to bring to the attention of those responsible for creating the legislation this lacuna (gap). If ever it was appropriate to be able to make such an order this is a case where there ought to be one made.''

Bradford Crown Court heard yesterday how Roberts, of Stainbeck Gardens, Cooper Lane, Bradford, met the girl in a McDonald's restaurant in Halifax. Prosecutor Simon Anderson said Roberts was told the teenager, who cannot be identified for legal reasons, was 18 and it was conceded by the Crown the girl looked mature in how she dressed.

Despite being told by relatives of the girl that she was only 13, the contact between them continued and in May last year Roberts told her he could not live without her.

They travelled together by coach to London where they slept in a doorway at Victoria station and survived on stolen food. The girl's father eventually found them, and Roberts and the girl returned to Bradford.

Roberts was warned by police to stop having contact with the girl, but eight days later they ran away again. Mr Anderson said this time Roberts appeared at her bedroom window and told her he would kill himself if she did not leave with him.

Roberts used stolen credit card details to pay for an estimated 40 coach trips around the country. Eventually arguments developed and the teenager said she wanted to go home, but Roberts threatened to take an overdose and even claimed to be suffering from terminal cancer. The girl herself tried to commit suicide by swallowing 24 painkillers.

In June the couple were found by at Carlisle railway station by the girl's grandmother after the teenager had telephoned her family.

Roberts' barrister, John Dunning, said a psychiatric report on his client highlighted words such as "immaturity'' and difficulties in forming relationships with the opposite sex.

He added: "Your Honour is dealing with the offence of child abduction but it's quite clear that (she) went with him.''

Before passing sentence Judge Kamil heard brief evidence from Roberts' pregnant 17-year-old girlfriend, who said they hoped to marry.

Roberts admitted two offences of child abduction and, following his sentence, two other sex allegations were ordered to lie on the file.

After the case, the girl's mother said she wished Roberts had been locked up for longer.

"I hate him," she said. "He blackmailed my daughter and manipulated her emotionally."