Lionel Messi will sensationally leave Barcelona, despite being widely expected to remain at the Nou Camp.

Messi became a free agent last month after his original contract with Barca expired but was set to re-sign with the club after agreeing to take a 50 per cent paycut on his previous contract worth in excess of £425million.

The player and club had agreed a new four-year deal that was to be signed on Thursday.

However, now the Catalan giants have confirmed the agreement cannot hold due to economic and structural obstacles put in place by the Spanish LaLiga.

In a shock statement on Thursday evening, Barcelona said: ''Despite having reached an agreement between FC Barcelona and Leo Messi and with the clear intention of both parties to sign a new contract today, it cannot be formalized due to economic and structural obstacles (Spanish LaLiga regulations).

Lionel Messi. PHOTO/COURTESY

''Given this situation, Lionel Messi will not continue linked to FC Barcelona. Both parties deeply regret that the wishes of both the player and the Club cannot finally be fulfilled.

''Barca would like to thank with all its heart the player's contribution to the enhancement of the institution and wishes him the best in his personal and professional life.''

Lionel Messi has been at the club for 21 years having joined the club as a 13-year old from Newell's Old Boys Club. 

He has won 31 major trophies including 10 Spanish League titles and 4 European Championship titles. And recently helped Argentine win the Copa America.

Messi will go down as the greatest ever player in the history of Barcelona and arguably the best player to ever grace the world of football.