An Egyptian court on Tuesday convicted a British woman of smuggling hundreds of powerful painkillers into the country, sentencing her to three years in prison.

The woman, 33-year-old Laura Plummer from Hull, has maintained her innocence since her arrest in October on arrival from Britain at Hurghada, a Red Sea resort city. She has insisted the Tramadol tablets were for her Egyptian partner, who suffers chronic back pain.

Tramadol is listed by Egyptian authorities as an illegal drug given its wide use as a heroin substitute. It's legal in Britain. Plummer's family says she had no idea that bringing the painkillers to Egypt was illegal. She did not try to hide them, they said.

The conviction came as a surprise since the hearing was supposed to be taken up by the argument of the defense. Plummer's lawyers immediately lodged an appeal.

Plummer, a shop worker, appeared in court on Monday, but the judged adjourned the hearings to Tuesday. Her mother, Roberta Sinclair, was in Hurghada for the trial.

Her sister, Rachel Plummer, said the family's hopes now hinged on the outcome of the appeal. "We're just hoping. Even half of that (three years' imprisonment) would be better. Anything less than three years. She doesn't deserve that."

The Plummers' local member of parliament, Karl Turner, said Foreign Secretary Boris Johnson and Foreign Office Minister Alistair Burt had raised her case with Egyptian authorities.

"I am hopeful that good sense will eventually prevail," he told BBC Radio 4's The World At One. "This is a damning indictment actually of the Egyptian authorities in the sense that good sense and fairness certainly hasn't prevailed in this case," he said.

"This is a decent woman who has made a terrible mistake who shouldn't be incarcerated in any prison, never mind an Egyptian prison."