Following the 29-year-old's 21-month prison sentence, the Spanish club have urged their supporters to let the forward know that "he is not alone"

Barcelona have set up a #WeAreAllLeoMessi support campaign in the wake of the Argentine’s tax fraud conviction.

The 29-year-old and his father have been sentenced to 21 months in jail, while the forward has been fined €2 million, after they were found guilty of defrauding Spain's tax authority of €4.1m between 2007 and 2009.

Messi and his father, who are not expected to serve jail time, have confirmed that they will appeal against the decision.

And now Barcelona have called on their fans to throw their support behind the Argentine by getting involved with the #WeAreAllLeoMessi campaign.

It's time to show our support: #WeAreAllLeoMessi. Add your voice to the campaign https://t.co/ld9dyidoXO pic.twitter.com/mNnfeZxl17 — FC Barcelona (@FCBarcelona) 9 July 2016

"Using the hashtag #WeAreAllLeoMessi while posting a photo or message with both hands open, the campaign is encouraging all Barça fans to express their sympathy for the greatest footballer in the world by voicing their unconditional support on social networks," read a statement on the club’s website.

"By making it clear that #WeAreAllMessi, we want Leo to know that he is not alone. All members, supporters clubs, fans, athletes, media and everyone else are invited to participate."