A Japanese couple performs at the 5th Tango Dance World Championship, in Buenos Aires, in August 2007. Argentina claims the dance form originated form the slums of Buenos Aires in the 1880s. (Natacha Pisarenko/Associated Press)

The governments of Argentina and Uruguay are now dancing to the same tune, uniting to petition UNESCO, the UN's cultural arm, to grant tango world heritage status.

Uruguay has always claimed that tango was born in the city of Montevideo with the original music composed by an Uruguayan, while Argentina has argued the passionate dance originated in the lower classes of Buenos Aires before the turn of the century.

Both countries have been at odds for more than a century, hurling charges of cultural appropriation at each other.

Yet, in spite of the decades of acrimony, each country's cultural ministry has decided it takes two to tango, and petitioned UNESCO together.

"The dominant factor is that tango is something we share," Eduardo León Duter, director of culture for Montevideo, told the Observer newspaper this week.

"While it's good that tango is spreading around the world, alterations invariably begin to creep in. There are certain original elements that need to be preserved."

A UNESCO official says a final decision will be made in September.

Tango traced back 1880s to slums of Buenos Aires

Each capital city hopes to build its own tango museum with permanent exhibits and to catalogue some 50,000 tango recordings.

Also on the dance card are a joint dance institute and a joint orchestra.

Both countries have some evidence to prove their point.

Historians can trace the dance form back to the slums and bawdy houses of Buenos Aires in the 1880s, to the European immigrants who sang of lust and betrayal.

However, the world's most popular tango song, La Cumparsita, was composed by Uruguayan Gerardo Matos Rodrígues 90 years ago and has spawned more than 2,500 variations. It became Uruguay's national hymn in 1998.