Mary Dejevsky was Moscow correspondent for The Times between 1988 and 1992. She has also been a correspondent from Paris, Washington and China.

Among the many charges levelled at Boris Johnson in his bid to become Prime Minister is his supposed predilection for big, self-aggrandising projects. Their unacceptability is underlined when they are described, as they often are, as grands projets – after the major capital projects launched by President François Mitterrand in 1980s France. This invites them to be dismissed as foreign borrowings which, when transplanted to inclement British soil, are bound to fail, but not before they have cost the taxpayer an awful lot of money.

Two examples are commonly cited to illustrate Johnson’s doomed romance with grands projets: the Emirates cable car and the aborted Garden Bridge across the Thames, both initiated when he was Mayor of London.

The cable car has indeed proved a largely unnecessary and expensive addition to the capital’s transport system (though it was, miraculously, completed in time for the 2012 Olympics).

How far the Garden Bridge can be classed as a BoJo folly is more questionable. It was the brainchild of Joanna Lumley, the actor and celebrity whose considerable powers of persuasion also convinced a hard-hearted government to allow several thousand former Gurkha soldiers and their families to resettle in the UK – an expensive undertaking that has not always ended well.

Of course, a wiser mayor than Boris might not have been seduced. But it is worth remembering that there was a time when the idea of an eco-friendly bridge wreathed in greenery was well received by Londoners – before the restricted access and the size of the future maintenance bill hit home.

And anyway, to describe either the cable car or the unbuilt Garden Bridge as a grand projet is quite wrong. They were at best minor vanity projects for an attention-seeking mayor.

Don't scorn Boris's ambition By Philip Blond

A grand projet is very different in its scale and ambition. It requires imagination, even vision – and yes, a wad of taxpayers’ money. But also a sense of both elevated purpose and the value of something that inspires.

The list of Mitterrand’s legacy includes the Pyramid at the Louvre, the Musée d’Orsay, the Opera-Bastille, the Grande Arche de la Defense, and the National (now Mitterrand) Library. The last, especially, has its critics – it ran late and vastly over-budget and used to be hard to reach, but it now takes its proud place in the Paris landscape.

In general, though, the finished products offer something impressive to show for the time and money expended – something that might hark back, in a way, to the great civic building projects of the past, or to the era of the great international exhibitions. The political will behind them also gives them the great advantage that they are seen through to completion, not abandoned half-way.

In fact, while much British scorn is reserved for other people’s grandiose schemes, it is not true that “we” can’t do them. How would you classify London’s Docklands, or the regeneration of Liverpool? Or the “new” universities of the 1960s and 1970s? Or Tate Modern, or the London 2012 Olympics?

Don't scorn Boris's ambition By Sam Jordison

This last was a grand endeavour that – eventually and despite much national pessimism – won huge public support and left a legacy now revitalising a once-depressed area of east London. Political will, space for imagination (that opening ceremony) and the focus forced by a deadline all contributed to its success. It bust the original budget, yes – but, how many would now say that it was not worth it, to have a nation feel better about itself?

In fact, far from dismissing grands projets, the UK would do well to consider a lot more of them. And not just them, but grands travaux – the more utilitarian, but no less inspiring, infrastructure projects at which the French in particular excel: the high-speed train network; the motorways, the Alpine tunnels, the bridges.

It is worth mentioning that two of these were the result of UK-French collaboration: the spectacular and supremely elegant motorway bridge across the Tarn at Millau (completed ahead of schedule in 2004), and the Channel Tunnel, which speeds more than 10 million people and 1.5 million lorries between the UK and France every year. Announced by Margaret Thatcher and François Mitterrand in 1984, the Eurostar was whisking its first passengers under La Manche 10 years later in a feat of engineering completed on time and rarely even remarked upon today.

Don't scorn Boris's ambition By Peter Franklin

Which is a good point to return to Boris Johnson and the potential there might be for whoever becomes the next Prime Minister to embark on some serious 21st century nation-building in the form of major new national infrastructure projects.

Johnson himself is reported to have broached the possibility of the Channel Tunnel being supplemented by a bridge during a Franco-British summit last year, only to be slapped down by the famously unimaginative Theresa May. Yet a bridge providing a road link was part of the original Channel Tunnel discussion. It is technically feasible; it would help loosen the pinch-points at either end of the Tunnel and send a forceful message about how the UK might be “leaving the EU, but not leaving Europe”, as the politicians like to say. It could also appeal to the French President, Emmanuel Macron – himself no slouch in the ideas department.

Johnson also highlighted the possibility of another bridge during the hustings this week in Belfast. There has been talk of a fixed link between Scotland and Northern Ireland for a while, with varying assessments of its feasibility. But what better way to send a message about the next Government’s determination both to preserve the Union and to look beyond the south-east than to initiate such a project?

Back to the south-east, and “Boris Island” airport is another Johnson project whose time may yet come. The new runway at Heathrow may now have parliamentary approval, but there are more consultations and more hurdles – especially ecological – to jump. With concern about climate change rising rapidly up the political agenda, and air and noise pollution increasingly recognised as harmful to health and quality of life, the marshes and birds of the Thames estuary may yet be sacrificed.

Another eco-friendly idea – also Johnson’s, as it happens – was to put the capital’s haphazard and congestion-prone North and South circular roads underground – as their equivalents mostly are in, say, Brussels and Paris. The idea was warmly received by local residents where plans were mooted, with the land freed above earmarked for housing and recreational space. But nothing came of it. Too difficult, too disruptive – and by then there was a new mayor.

Don't scorn Boris's ambition By Paul Embery

Contrast the travails of Crossrail, designed to ease journeys into and across London – now running way over budget and more than two years (if we are lucky) over time. And then there’s the controversial north-south high-speed railway, HS2, which may never be built. The difficulties have been not only with the planning and implementation, but with the “selling”.

Where is the vision of what a more direct, faster, north-south railway could provide? Why was the chance to transform travel around the north of England, or the currently parlous east-west routes, not highlighted? Why has it all been so London-centric?

And why has no one picked up on the opportunity, since the Houses of Parliament need to be vacated for refurbishment, to look seriously at the possibilities of a new building – or even a capital – elsewhere? Or even an imaginative temporary structure, such as the Serpentine Gallery manages to construct on a small scale every year? Current plans are for an extraordinarily expensive adaptation of an existing building on Whitehall. Where is the imagination?

It is beyond time for the UK to drop its supercilious and defeatist attitude to grands projets, and recognise that they can have multiple benefits.

At best, they can inspire, they can add aesthetic and cultural value, they can improve public facilities on a scale that is beyond the capacity of many local authorities. With political will behind them, they do come to fruition.

The next Prime Minister and his government should take a lead, but also invite ideas from around the country. They might be surprised at the vision and practical ambition that is out there, just waiting to be freed.