AN attempt to increase the sentence of a father jailed for killing his six-week-old baby daughter has been dismissed by top judges.

Andrew Ashurst, aged 23, of Blake Avenue, Atherton, was jailed for three years at Liverpool Crown Court in May after he pleaded guilty to the manslaughter of baby Leah.

But lawyers for the Attorney General, Lord Goldsmith QC, argued the jail term was "unduly lenient" and urged three Appeal Court judges to up the killer's sentence.

On Thursday, Lord Justice Rose, sitting with Mrs Justice Hallett and Mrs Justice Dobbs at London's Appeal Court, refused the application, saying the term meted out was "lenient, but not unduly so".

The judge said Leah was born on November 15, 2002. The relationship between Ashurst and the baby's 16-year-old mother had been "strained".

The couple lived together, both before and after the birth, in a house in Bolton, near the homes of both their respective families.

On the night of December 22, 2002 -- following an evening of arguments between the couple -- Leah spent a restless night in a Moses basket in her parents' bedroom.

At about 3am on December 23, Ashurst got up and took his daughter downstairs, claiming that he wanted to allow his partner to sleep.

But he did not reappear until about 7.20am the following morning, when he awoke his girlfriend and told her Leah was not sleeping properly.

The mother then noticed that her body was cold to the touch, and her eyes in a "fixed position". She also noticed several marks on her and blood around the nose.

Leah was rushed to hospital, but tragically died on Christmas Day 2002. Police were called to the hospital after death by unnatural causes was suspected.

Ashurst was eventually arrested and charged with murder in August 2003. However, he later admitted the less serious accusation of manslaughter on the basis that he shook Leah after having lost his temper because she would not sleep.

Lawyers on behalf of the Attorney General today argued that Ashurst's sentence was "unduly lenient" and "failed to reflect the culpability of Ashurst and the distress caused by the offence".

Dismissing the application, Lord Justice Rose described the jail term as "lenient", and said he would have expected the trial judge to have imposed a sentence of three-and-a-half-to-four years.

But he added: "However, we entertain some doubt as to whether in the circumstances, this sentence can be described as unduly lenient. Accordingly, in these circumstances we will not interfere with the sentence set by the trial judge, and this application is dismissed."