The government's failure to ban smacking means it is failing to fully honour a pledge to "keep children safe", according to a parliamentary committee.

The joint committee on human rights issued the warning as it published a report setting out the government's views on the UN Convention on the Rights of the Child (UNCRC).

MPs and peers welcomed much progress that had been made in improving child welfare.

But smacking was highlighted as one key issue where the government's position was "disappointing".

The joint committee argued that children should have the same legal protections from assault as adults.

"The government struggles to support the reasonable chastisement defence, which continues to be incompatible with its obligations under the Convention on the Rights of the Child," said the report.

In their response to a previous committee report on issues related to the UNCRC, ministers pledged that the attorney general would keep the defence under review, but added that so far the evidence suggested it was being "used properly".

But the committee said that the supporting data for this view should be published and the word "properly" should be defined to prevent the attorney general's conclusion being "meaningless".

And the government was also criticised for failing to "suggest any constructive alternatives to corporal punishment for disciplining children" in the recent green paper.

Other key concerns for the MPs and peers included the lack of an official framework for children's rights.

"There is insufficient recognition that issues like the age of criminal responsibility, conditions in custody or reasonable chastisement, engage the human rights of children," said the committee.

The committee concluded that omissions such as these "hinders progress towards building a culture of respect for the human rights of children and displays insufficient compliance with obligations under the UNCRC".

"We acknowledge and welcome the steps taken by the government and the devolved institutions to improve respect for and protection of the rights of children in the UK," it added.

"This protection will be enhanced when there are commissioners for children and young people operating effectively in all parts of the nation.

"The enhancement of a culture of respect for children's rights is a progressive goal. Although we have reservations about aspects of government policy, legislation and administrative practice, the net effect of recent developments has been generally positive.

"We remain disappointed, however, at the apparent reluctance of the government to be more explicit about basing what it does for and on behalf of children within the framework of the goals and guarantees set out in the UN Convention on the Rights of the Child."