Nigel Gresham and Thomas Duffield are to face England's most senior judge for the next chapter of what could prove to be a decisive moment in setting legal precedent.

The two men were both convicted of causing death by dangerous driving following accidents in Lincolnshire in 2007.

Four of Gresham's children died when the family Land Rover plunged into the River Witham at Tattershall Bridge in September 2007.

Duffield ploughed into cyclist Leigh Dolby at Sudbrooke, near Lincoln, in August 2007.

Both were sentenced at Lincoln Crown Court earlier this year.

On each occasion the sentencing was followed by an outcry by those who said the punishment was not enough.

The Attorney General, Baroness Scotland, agreed that the jail terms appeared 'unduly lenient' and referred them to the Court of Appeal.

Next month the Lord Chief Justice, Lord Judge, will hear both cases, and a third, on the same day to decide if Gresham (37) and Duffield (20) got off too lightly.

The rulings handed down in the cases will form legal precedents – which tells crown court judges throughout England and Wales how the law is to be interpreted and how sentencing guidelines are to be applied.

The Dolby family's solicitor, Gary Phillips, of Lincoln firm Sills and Betteridge, said: "If a case is listed before the Lord Chief Justice, it means he is going to be saying something on policy.

"Whatever is said will influence sentencing decisions up and down England.

"That means that this case, which was also important to the Dolby family, is now also important in a different way.

"Whatever the outcome now, the Dolby family is having this case reviewed by the most senior judge in England.

"For the Dolby family, it is about closure and a matter where they thought the sentence handed down was inadequate."

Duffield, from Sudbrooke, is serving a 12-month sentence for causing death by dangerous driving.

He was driving his father's Toyota Corolla when it ploughed into Mr Dolby (54), from North Hykeham, killing him instantly.

Duffield was 18 at the time.

Daniel Dolby (32), who lost his dad in the tragedy, said the news was "the best we could have".

"It's fantastic because you watch the news and see the inconsistencies in sentencing that is going on," he said.

"My dad's legacy will hopefully be that other people will not have to go through what we have gone through but that things will be done differently in future."

Nigel Gresham was sentenced to two years in prison for four counts of causing death by dangerous driving.

The court heard that his Land Rover was a "death trap" and that he had been speeding just before the crash.

The third case is that of a Suffolk woman, Philippa Curtis, who caused a high-speed crash after talking and texting on her phone.

Curtis (21) was jailed for 21 months for causing the death of Victoria McBryde (24).