A Conservative peer has claimed that many comprehensive schools “lack discipline” and hold back more able children.

Lord Cormack, a former teacher, was speaking during a debate on a proposal to phase out the country’s remaining grammar schools – including the 32 in Kent.

The debate coincided with the launch of a cross-party campaign group called "Times Up For The Test" drawing together opponents of grammars.

But Lord Cormack told the House of Lords: “The real problem in education, more than any other single factor, is discipline.

"You need discipline for learning, but so many of our large comprehensive schools do not have good discipline.

"One sees the shining examples of those that do, but it really is crucial that we concentrate on that – I would say more than any other single factor.

"If there is no discipline, children cannot properly learn. They go astray and their parents are let down.”

He urged the government to resist efforts to end the 11-plus, saying “it would do no service to abolish a particular group of schools that contains some of the most remarkable schools in our country”.

The call for legislation to gradually phase out selective schools and end the 11-plus is being proposed by the former leader of the NUT Baroness Blower.

She said it would not be difficult to devise a strategy in which grammars could gradually phase out selection.

Opening a debate in the Lords on Friday, she said: “I believe profoundly that it is an important principle that the education service should provide access on an equitable basis to all children and young people.

"This is not, of course, what happens in the 35 local authorities where access to certain state-funded schools is on a selective basis.”

Exam results in non-selective schools were “statistically significantly below the national average because of the nature of their skewed intake,” she said.

"The 11-plus has become a test that favours those with the ability to pay for tuition..."

“Comprehensive schools raise the attainment of all children," she added. "More children do better in a comprehensive system.

"The attainment gap, which has increased since the pandemic, between disadvantaged and more advantaged pupils, is narrower in comprehensive schools.

"The 11-plus has become a test that favours those with the ability to pay for tuition, a suggestion supported by the fact that only 3% of children in grammar schools are entitled to free school meals.”

Among supporters of a comprehensive system was Labour peer Lord Hunt of Kings Heath, who said: “Those who promote grammar schools only ever talk about the pupils who pass the test – they never mention the impact on those who fail.”

Current legislation does not permit opening new grammar schools but does permit extensions to existing ones.

Kent was the first in the country to propose such an extension when in 2017 it created an annexe at Sevenoaks operated by the Weald of Kent Grammar School.

Critics have said such extensions are a back door to opening of more grammars.

However, demand for places at selective schools appears to be growing. Around 1,000 more children took the test this year – an estimated 17,000.