It is one of those extravagant but vote-winning political projects that will almost certainly be filed under "nice-idea-but-who-will-pay?"

Nathalie Kosciusko-Morizet, the centre-right UMP candidate for mayor of Paris, has livened up an otherwise lacklustre campaign with a series of stunning photographs of how the city's ghost metro stations might be used.

… or a refectory-style restaurant

Futuristic photographs show the Arsenal station, near the Bastille – closed in 1939 at the start of the second world war and never reopened – transformed into a gleaming swimming pool, theatre and concert hall, nightclub, art gallery and even refectory-style restaurant.

Kosciusko-Morizet, known by her initials NKM, says the plans drawn up by two Paris architects are "examples of the field of possibilities" of uses for the underground stations, and that if elected she will ask Parisians for their own ideas.

… or a theatre and concert hall

There are a total of 16 ghost stations on the Paris metro; stops that were closed or never opened. Most of them were shut up in 1939, while two of them were built but never opened to the public.

Some have been temporarily transformed for advertising campaigns or film settings, as was the original Porte-des-Lilas, closed in 1935 but used as a backdrop for the Fabulous Destiny of Amélie Poulain. Part of the now-abandoned Saint-Martin stop, closed in 1939, is used as shelter for the homeless during the winter.

… or a nightclub

The stunning photographs, however, have failed to boost support for NKM, who is struggling to catch up with Socialist Anne Hidalgo, the frontrunner in the mayoral race and protege of the current mayor, Bertrand Delanoë. An Ifop survey for Le Parisien published at the end of January suggested 39.5% of Parisians would vote for Hidalgo in the first round on 22 March, and 54 % in the second round on 30 March, with 36.5 % then 46% voting for NKM. The three other candidates from the far left Parti de Gauche, Europe Ecologie Les Verts and the far-right Front National would trail behind with scores failing to reach double figures in the final round, according to the poll.

The Paris metro has been something of a thorny subject for Kosciusko-Morizet, a one-time government minister. During Nicolas Sarkozy's unsuccessful 2012 re-election campaign she was mocked for not knowing the price of an underground train ticket (she said €4 instead of €1.70). Then in November she was ridiculed as being out of touch with the real world after describing one of the network's busiest – and some say dirtiest – lines as "a place of charm".