Lawyers for an Egyptian-Canadian journalist convicted in Cairo of terrorism charges have filed an appeal in an effort to secure a new trial, his family said Wednesday.

Mohamed Fahmy was working for Qatar-based satellite news broadcaster Al-Jazeera English when he was arrested on Dec. 29 along with two colleagues -- Australian correspondent Peter Greste and Baher Mohamed, an Egyptian producer.

The trio were accused of supporting the banned Islamist Muslim Brotherhood group of ousted president Mohammed Morsi. They were also charged with fabricating footage to undermine Egypt's national security.

The journalists denied all charges against them saying they were just doing their jobs.

Fahmy and Greste were later found guilty and sentenced to seven years in prison, while Mohamed was sentenced to 10 years. The judge's sentencing reasons said the three journalists were brought together "by the devil" to destabilize the country.

The trial was denounced as a sham by many international observers.

Adel Fahmy said his brother initially was "very stubborn" and refused to appeal his conviction because he was still "infuriated and frustrated from the verdict."

"He didn't have enough confidence in the whole process," he said.

Mohamed Fahmy explained the reasons for his reluctance to appeal in a letter he sent last month to Canadian Journalists for Free Expression.

"If an appeal is accepted months from now, we will be paraded in whites again in the circus of a retrial," he wrote.

It took time and efforts from his family and the Canadian Embassy in Cairo to change his mind and convince him to file the appeal, said Adel Fahmy.

"This is an essential step, we have to explore all the routes and we have to take this conventional step as well judicially," he said.

If the appeal is accepted, then a court date will be set, Fahmy said, adding that this "could be many months away."

A successful appeal would mean a retrial and a possible overturning of the verdict.

He said the appeal argued that the sentence should be overturned due to "all the invalidities and flaws in the judicial process that took place" during the initial trial.

The Fahmy family is not depending solely on the appeal's success and is asking for international pressure that might result in an exceptional overturning of the conviction.

They are also pursuing a pardon from Egyptian president Abdel-Fattah el-Sissi, who had initially said he wouldn't interfere in the judicial process.

Last month, El-Sissi's tough stance seemed to soften when he told editors of certain Egyptian media outlets that the heavy sentences in the case have had a "very negative" impact on Egypt's reputation.

Some observers have suggested Fahmy's case forms part of the Egyptian government's efforts to target Qatar, which was a close ally of Morsi. Egyptian authorities had accused Al-Jazeera of bias toward the Muslim Brotherhood and Morsi, but the network has denied the allegations.

Foreign Affairs Minister John Baird has acknowledged the sensitive relationship between the two countries, and has said "bullhorn diplomacy" won't win Fahmy's release. Baird has said Canada is pursuing all legal avenues to secure Fahmy's release.

Fahmy's family moved to Canada in 1991, living in Montreal and Vancouver for years before eventually moving abroad for work, which included covering stories for the New York Times and CNN.

Adel Fahmy said the Canadian government has been exerting a lot of effort behind the scenes, but more needs to be done.

"This is the most central time for them to really apply the necessary push or pressure to get the favourable result out of the appeal," he said.

"Hopefully it succeeds and translates into a retrial to avoid serving the sentence, of course, which is absolutely ridiculous."