Doctors treating seriously ill baby Charlotte Wyatt will still have the option not to resuscitate her if she stops breathing after her parents failed in their attempt to get a court order lifted today.

Darren and Debbie Wyatt believe their daughter has shown considerable signs of improvement since last October, when a high court judge agreed with doctors that her quality of life was so bad that she shouldn't be subjected to further aggressive medical treatment.

But Lord Justice Hedley gave the couple permission to bring new medical evidence to court at a further hearing before Easter to back their claims that her condition had considerably improved.

The judge said he was "delighted" by signs that the 15-month-old was making medical progress.

"Nobody who knows this case can derive anything other than pleasure from that," he said.

Lawyers for the Wyatts had argued that the order should be suspended until further medical evidence on Charlotte's condition was available, but the judge refused.

Explaining his decision, Mr Justice Hedley said there was no substantial medical evidence to support the Wyatts' assertion that Charlotte's health had dramatically improved.

"With that consideration in mind ... I am not prepared to stay the order during the period between now and when the case is next before me," he said.

At today's hearing, the team of doctors treating the girl said her serious, underlying condition had not improved and that her brain was not growing.

The Wyatts lawyer said the couple, "naturally very disappointed", were considering taking the case to the court of appeal.

A statement by the Portsmouth Hospitals NHS Trust, which is caring for Charlotte, said it was grateful for the sympathetic and humane way the judge was handling the case.

"We are also pleased he recognises that the high standard of care is producing benefits for Charlotte, but the underlying, very serious condition is unchanged," a spokesman for the trust said.

The judge said medical evidence to be brought before him at the next court hearing, scheduled to take place before Easter, might require him to revise his decision.