More than a fifth of children in Brighton and Hove have missed out on their first choice school in the first year the lottery admissions system has been used.

The city has seen a slump, understood to be six per cent, in the number of youngsters allocated places at their preferred school.

The fall has coincided with drops across the country including in East and West Sussex.

It has been blamed on the enforced introduction of a new system across the country by the Government.

The new equal preference system means that education bosses must try to put pupils into one of their three choices of school - instead of trying to get as many as possible into the schools they want to go to most.

Despite the slump Conservatives in Brighton and Hove said today they would defy their national leadership by persevering with the controversial lottery system which has been used to allocate places at two oversubscribed schools.

Shadow education secretary Michael Gove today branded the use of ballots as "completely inequitable and unfair".

Councillor Vanessa Brown, the Tory education spokeswoman on Brighton and Hove City Council, said the scheme had proved to be successful in its first year and would not be replaced in a knee-jerk reaction.

And she said the council's Conservative administration had no intention of calling for a change.

She spoke before 2,355 Year 6 pupils in the city and their families were receiving letters tomorrow telling them which secondary school they had been allocated places at for September.

The Argus understands the number of the ten and 11-year-old children who missed out on their first preference place rose from around 16 per cent in 2007 to around 22 per cent this year.

Coun Brown, who tonight would not confirm or deny the figures, said: "We are going to concentrate on what works best for the people of Brighton and Hove and the indications are that the current measures have made an improvement."

She stressed that despite her faith in the system, it had been introduced by the Labour administration which controlled the council before last May's elections.

The council has refused to issue any information about the outcome of the admissions process until 10am tomorrow.

It is understood officers are confident the system will show an increased number of children have been allocated one of their three preferred schools, compared with last year's 93.3 per cent.

The Government now considers that measure as a key indicator of an admissions system's success.

The enforcement of the equal preference system instead of its predecessor, the first preference first, means councils must strive to get children into one of their parents' three choices, rather than just trying to achieve their top option.

Coun Brown said: "It was inevitable there would be a drop in first preferences allocated because we have been forced to implement equal preference. That would have happened regardless of whether there was a lottery."

In East Sussex the number of pupils allocated their first choice fell from 87.38 per cent in 2007 to 84.9 per cent this year. The amount being placed at one of their three preferences also fell, from 93.03 per cent to 92.33 per cent.

Figures for West Sussex were not available tonight but it is understood the county also experienced a fall in the number of pupils allocated to their first choice school.

The controversial lottery in Brighton and Hove has been used as a tiebreaker as the final stage of a new system of single and dual catchments and the use of equal preference.

The Argus revealed in November that in the two dual catchments there was huge oversubscription at one of the two schools, meaning the lottery would definitely be used.

More than 900 pupils have gone through the process to see who got the 600 places available.

Parents across the city were anxiously awaiting the outcome tonight.

Dentist Priti Barua, 40, of Dyke Road, Brighton, lives in the dual catchment for Blatchington Mill and Hove Park schools in Hove.

She said she was nervous over whether her daughter, Prisha, ten, and her friends at Stanford Junior School in Stanford Avenue, Brighton, would all go to the same secondary school and whether they would get their first choices.

She said: "We are the guinea pigs for their experiment and we are not happy about it. We do not have any certainty about what will happen."

Mrs Barua said her daughter and several friends had passed entrance exams at an independent school and the parents would decide whether to take them up based on the outcome of the lottery.

For the facts and figures of Brighton and Hove's admissions system visit this site after 10am tomorrow.

Has your child found out which school they have been allocated? The Argus would like to hear from you. Call us on 01273 544548.