A rare manuscript handwritten by Robert Burns, which has been in Paisley's collection for two centuries, has been confirmed as the world's only surviving copy.

Donated to Paisley around 200 years ago, the piece, Sir, Yours This Moment I Unseal, dates back to 1786 and has been described by an expert as one any major library in the world would be proud to have.

It will go on display in Paisley Museum this week in time for Burns Night on Monday and comes as Paisley’s bid to be UK City of Culture in 2021 gathers pace.

The manuscript was originally donated to Paisley by John Clarkson of local thread-makers McGavin and Clarkson at a time when the town was a thriving global textile hub. The short verse shows Burns accepting an invitation to a party or social event

Professor Gerard Carruthers, co-director of the Centre for Robert Burns Studies at Glasgow University, said: “Although this is not one of Burns' major works, it is a hugely important manuscript.

“It is one that any collector, town in Scotland or major library in the world would be proud to possess.

“The text is an upbeat poetic squib dating from 1786 and Burns’ first flush of fame.

The item was originally kept in the collection of the institutions that later formed the current Paisley Museum and Central Library and has been in secure storage in the town in recent decades.

In November last year, proposals were revealed for a £56.7m revamp of Paisley Museum with plans to turn it into an international-class destination based on the town’s unique textile history as a flagship project connected to the City of Culture bid.

Renfrewshire Council has also set aside £3.7m for a publicly-accessible museum store to open on the High Street by 2017.

Councillor Mark Macmillan, chairman of the Paisley 2021 Partnership Board, added: “We already knew the town's museum collection was of international significance, but this latest discovery shows we have another star item in our possession.

“As the town’s UK City of Culture bid moves closer, we will be looking to showcase the full scale of that collection to residents and visitors through the revamped museum and museum store.”