Extra 11 Plus marks should be awarded to children who get free school meals to improve their chances of getting into grammar school, a report has said.

The report from the Education Data Lab says "the way the 11 Plus works in Kent is akin to rolling a loaded dice" as disadvantaged children are less likely to get in.

In Kent in 2016, 5,249 children went to grammar school and 16,588 went to a non-selective secondary.

According to the report, children who are eligible for free school meals (FSM) are less likely to sit the 11 Plus and when they do, they are far less likely to pass it.

They say their analysis suggests the selection process in Kent does not always identify "the most academically capable children".

Just 12% of FSM-eligible students pass the test, compared to 30% of those not who do not get free school meals.

The Education Data Lab report said: "Kent state primary schools are explicitly asked not to prepare their pupils for the 11 Plus.

"This means that the only students who are able to gain familiarity with the reasoning questions used are those whose parents help them practice, those who pay for private coaching, and those at private schools.

"We think this lack of specific 11 Plus preparation among some students – such as FSM-eligible students – explains why the FSM-gap in average paper marks is greatest in reasoning, at 7.7 points, compared to maths (6.8 points) and English (3.9 points).

"If the 11-plus is a dice, then the reasoning component contributes to the dice being loaded against disadvantaged children."

The research organisation wants Kent County Council to improve the chances for disadvantaged children by allowing state primary schools to provide 10 hours of practice on reasoning-style questions to all students, and automatically award FSM-eligible students extra marks on the 11-plus, particularly for the reasoning paper.

Their report is based on data obtained under the Freedom of Information Act by the Kent Education Network, a group opposed to selective education.