This article is more than 10 months old

This article is more than 10 months old

The French government has rebuked the army general charged with the rebuilding of the fire-ravaged Notre Dame Cathedral after he told the chief architect to “shut his mouth”, in a sign of tensions over the cathedral’s future appearance.

Gen Jean-Louis Georgelin lost his cool with Philippe Villeneuve in a dispute over whether to replace the spire, which collapsed in the fire in April, with an exact replica or a modern alternative.

“As for the chief architect, I have already explained that he should shut his mouth,” Georgelin said to gasps of astonishment at a meeting of the national assembly’s cultural affairs committee on Wednesday.

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The culture minister, Franck Riester, tweeted on Thursday that Georgelin’s outburst was “not acceptable”, adding: “Respect is a cardinal value in our society. As public officials, we must be exemplary.”

The president, Emmanuel Macron, who appointed Georgelin to head the reconstruction project, has said he is in favour of adding a “contemporary” touch to the spire. But Villeneuve has insisted it must be rebuilt exactly as it was before.

Georgelin, a former army chief of staff, said the final decision would be made in 2021 and he called for the “hustle and bustle” over the issue to stop in the meantime.

He confirmed the five-year timeframe set by Macron for rebuilding the cathedral – a deadline some experts see as too ambitious. Villeneuve has said the target can be met only if the spire is rebuilt to resemble the old structure.

Play Video 1:11 Notre Dame Cathedral: before and after the devastating fire – video

Notre Dame, part of a Unesco world heritage site on the banks of the River Seine, lost its gothic spire, roof and many precious artefacts in the fire. Paris prosecutors said in June that a cigarette or an electrical fault could have started the fire, and they opened an investigation into criminal negligence.

Last month the culture ministry said nearly €1bn (£860m) had been pledged or raised for the reconstruction.

The cathedral is still enveloped in scaffolding and plastic sheeting. Georgelin told MPs it “remains in danger”.

“The phase of securing the edifice is not over. It will be done when the scaffolding around the spire has been dismantled,” he said, warning that winter gales could destabilise the temporary protective structure.

On the positive side, Notre Dame “no longer seems to be emitting lead” – a concern shortly after the disaster when hundreds of tonnes of lead in the roof and steeple melted.

Villeneuve, the cathedral’s architect since 2013, said last month: “Either I restore it identically, [and] it will be me [as the architect], or they make a contemporary spire and it will be someone else.”