Why are we asking this now?

Because that's one of the more controversial suggestions from a think tank which is looking into how Britain can alleviate its rather desperate allotment shortage. According to the New Local Government Network, persuading councils to turn over vacant brownfield sites – and landowners to give up under-used parts of their private estates – would quickly free up huge tracts of land that could easily be turned over to growing food.

The think tank's director, Chris Shipley, who is also a former MP, has even suggested that the Royal Family should hand over some of their land. "I am sure that as a vocal advocate for farming and the countryside, that Prince Charles and the Duchy of Cornwall will be supportive of the idea," he said.

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How bad are the shortages?

Pretty bad. The number of allotments available to the public has remained relatively constant over the past decade but what seems to have taken everyone by surprise is the amazing demand for patches of land to grow your own.

Jeff Stokes, the national secretary of the National Association of Allotments and Leisure Gardens, says: "Demand for allotments has mushroomed in the past five years. People are now so much more concerned about how much food is imported vast distances to our supermarkets when they could be grown at home. But the supply hasn't increased with the demand."

How many people are waiting for an allotment?

About 86,000 people are confirmed as being on a waiting list but not all local authorities have provided full details of their shortages. Campaigners believe the nationwide shortage is anywhere from 100,000 to 150,000 individual allotments. In some areas where demand is particularly high – primarily inner-city London and the North-east – it can be decades before an allotment becomes available to someone on a waiting list. To give you an indication of how much more back in vogue allotments now are, in 1996 the waiting list was just 13,000.

Why are there so few allotments available?

Because on our crowded little island, land has become an increasingly finite resource. In the 1940s, when millions of Britons were encouraged to "Dig for Victory" during the Second World War, there were an estimated 1.4 million individual allotments across the nation. But as supermarkets began taking over our high streets throughout the 1980s and 1990s (flying in a scintillating array of vegetables and fruit from around the world, whatever the season) the demand to grow your own food locally quickly plummeted. Keen to free up land to alleviate housing shortages or generate spare income, local councils began selling off their disused allotments. Now there are just 200,000 plots available, well below the overall demand.

How can we create new allotments in cities?

By being a little innovative. While Britain may be a heavily populated island with a growing population, allotment campaigners say even in heavily-built areas space can still be found. London, for instance, has initiated a new campaign to create 2,012 new growing spaces for the 2012 Olympics by converting roof space, disused waterways and railway yards. Local borough councils have also been asked to persuade hospitals and schools to turn their bits of unused land over to gardening.

What else does the report suggest?

The New Local Government Network believes the easiest and quickest way to create new allotments would be to target brownfield sites and wasted private land. Britain has an estimated 12,710 hectares of vacant brownfield land, at least 85 per cent of which is located within 500 metres of an urban area. Even turning some of these sites into temporary allotments could help alleviate demand very quickly.

Private land could also be used to create a more sustainable food economy. Currently 70 per cent of land in Britain is still owned by 1 per cent of the population. Other than the Royal Family, which owns 677,000 acres, Britain's largest landowners include the Duke of Buccleuch and Queensbury (207,000 acres), the Duke of Northumberland (130,200 acres) and the Duke of Westminster (129,300 acres).

How can we persuade landowners to lend their land for allotments?

Firstly by appealing to their altruistic side or by offering tax incentives. The Landshare website, where people with spare plots of land can advertise to others looking to grow their own vegetables, has already shown how many people are more than willing to let others borrow their property in order to grow food. The website was only launched in the spring and already more than 1,000 people have offered land for free.

But in areas where demand for allotments is acute, the report's authors believe the Government should create a Large Private Estate Commission which would "be empowered through statutory legislation to temporarily transfer" land to the people if a landowner refuses to countenance the redevelopment of vacant land.

Isn't that quite controversial?

Oh yes. Confiscating land, even if it is unused and will only be leant to someone temporarily, is a hugely controversial issue. For many it would represent an unacceptable level of interference by the state – akin to the kind of mass land-redistribution schemes favoured by numerous communist governments in the last century. But others believe borrowing land that would otherwise be left vacant is morally acceptable.

In the past year Britain's squatting movement has increasingly begun to argue that in these difficult economic times where many are priced out of the property market, an occupied home is still better than an empty one. Gardeners are also getting in on the act. Inspired by a similar movement in America, so-called "guerrilla gardeners" have begun growing produce on various bit of land, both private and public, regardless of whether they have permission or not.

Do we really need allotments?

Some might argue that an allotment is a luxury acquisition. But for those who are concerned about our future food sources, allotments make both economic and environmental sense. Last year the UN announced that food production would have to increase by 50 per cent by 2030 in order to cope with rising demand, and it cannot all be air-freighted into the country.

Whatever happens to the global food supply, it is clear that we will have to start growing more food at home, and it makes economic sense. According to Terry Walton, who runs Radio 2's "house allotment" in the Rhondda Valley, growing a kilogram of carrots on an allotment costs just 4p compared to 78p in a supermarket. Potatoes, meanwhile, cost just 40p/kg from an allotment and £1.08 on the high street.

You also save a huge amount of money in plastic packaging. Each year an estimated 6.3 million tonnes of packaging comes into British homes, at a cost of £450 to the average family – the equivalent of a sixth of the average family's annual food budget.

Is it time unused land was seized in order for us to be more self-sufficient?

Yes...

*There's an enormous shortage of allotments and lots of under-used land held privately

*The land could be used temporarily and returned to the landowner if they want to develop it

*No one is saying landowners should be forced to hand over property, just a little more altruistic

No...

*Seizing land, even temporarily, from landowners can never be acceptable in a free-market economy

*It should be the Government's responsibility to find land for allotments

*Demand for allotments comes and goes. Growing your own may go out of fashion once more

j.taylor@independent.co.uk