A student who fell asleep at the wheel and killed a man after partying the night before has been jailed for three years.

Alisdair Grant caused a head-on smash in which Gerry Lewis suffered fatal injuries in East Ayrshire in March 2014.

The 21-year-old had only just returned to the roads after serving a year-long drink-driving ban.

Grant was sentenced on Wednesday at the High Court in Glasgow after pleading guilty to a charge of causing death by dangerous driving.

The collision occurred on the A719 close to the Ayrshire village of Waterside.

Grant, of Kilmarnock, was driving his brother's car despite feeling the effects of drinking the previous evening.

Prosecutor Mark McGuire told the court: "Text messages recovered from his mobile phone sent that day indicate he had been partying heavily the night before.

"The texts made it clear that Grant was tired."

Mr Lewis was meanwhile driving his Suzuki 4x4 in the opposite direction. The 54-year-old was travelling with his wife Sarah to visit his widowed mother in Glasgow.

The hearing was told as the two vehicles approached, Grant's Fiat drifted "without warning" into the path of Mr Lewis's car causing a head-on collision.

Mr Lewis, a conservationist with North Lanarkshire Council, was cut free from the wreckage and later died from his injuries.

Mr McGuire told the court: "Gerry Lewis was a much loved husband and family man. His wife and wider family miss him dearly."

Judge Lord Boyd described the teenager as having a "cavalier attitude" as he handed him a jail sentence and banned him from the roads for four years.