Long-awaited restoration of Leonardo masterpiece delights critics in the Louvre

A much-disputed face-lift given to Leonard da Vinci's final masterpiece was unveiled to the public at the Louvre in Paris yesterday.

The Virgin and Child with Saint Anne has been restored to what may be its original 16th-century colours. Although the restoration provoked controversy when it began last year, most French art critics and members of the public appeared delighted with the sparkling result yesterday.

One critic, Vincent Noce of the Libération newspaper, said that the "meticulous restoration" provided a powerful argument for the cleansing of other Leonardo works in the Louvre – including the Mona Lisa itself.

In an exhibition lasting until 25 June, visitors to the Louvre can compare the painting with the Leonardo "cartoon" from the National Gallery in London, which has been allowed to leave Britain for the first time since it arrived in the 18th century.

Both masterpieces, brought together for the first time in 500 years, show the infant Jesus on the lap of the Virgin Mary, under the loving gaze of his grandmother, Saint Anne. In the painting, unfinished at Leonardo's death in 1519, Jesus is cuddling a lamb. In the National Gallery charcoal drawing, dating from 1501 and rescued from private sale for the British national collection 50 years ago, Jesus is leaning forward to play with an infant John the Baptist.

The Saint Anne painting, commenced around 1508, was one of a number of works, including the Mona Lisa, which Leonardo (1452-1519) loaded on to the back of a donkey when he emigrated to France at the invitation of King Francis I in 1516.

After the painter's death at Amboise, on the river Loire, three years later, the paintings passed into the French royal collection. Over the centuries, the painting of Saint Anne became disfigured by yellowing varnish and botched 19th-century restoration efforts. A first attempt to restore it was abandoned 17 years ago.

Another attempt, using subtler techniques, was approved in 2009. Two of France's foremost restoration experts resigned from a Louvre advisory committee last year protesting that the cleansed painting would be brighter than Leonardo intended.

Digital recreations have suggested recently that the sombre Mona Lisa was once as bright and fresh as the restored Saint Anne, but there are no plans to give it similar treatment.