Ministers are considering using Australian-style tactics to block migrant boats leaving France amid amid a sharp rise in the number of people making the treacherous journey across the channel.
Australia's successful 'push back' method is used to stop illegal migrants arriving from Indonesia and is one option being considered by government, according to sources.
But some are concerned that such drastic interventions could lead to drownings - with some questioning whether the move would be legal in the first place.
Migrants were photographed using shovels to paddle their boats (pictured) and some have used paddling pools instead of proper vessels
One source in the Defence Ministry said it was 'completely potty' to get the navy involved, The Times reported.
Almost 4,000 migrants have crossed the Channel to the UK so far this year, according to analysis of Border Force figures.
In some cases, makeshift flotation devices have been created out of household items.
A man was found with empty lemonade bottles strapped to his body just four miles off the French coast in a highly-dangerous bid to swim to Britain.
In another shocking case, a group tried to get to the other side of the channel in a children's paddling pool while some have tried wooden boats or kayaks.
This is thought to be more than double the total for the whole of 2019 where fewer than 2,000 are believed to have arrived in the country.
Pictured: A swimmer crosses the English Channel as, in the background, a dinghy carrying migrants is escorted by French border police on Friday
Almost 4,000 migrants have crossed the Channel to the UK so far this year. Pictured: Children are picked up by the Border Force vessel Hunter after being brought into Dover, Kent on small boats crossing the English Channel
Border Force officer escorts a young family thought to be migrants from a Border Force vessel in Dover
On current trends, around 7,500 migrants will cross the Channel by the end of the year, according to an analysis of official figures by Migrationwatch.
This would be nearly four times the 1,892 that entered the UK via the crossing in the whole of 2019, the campaign group projected.
Immigration still too high – poll
More than half of Britons think immigration is still too high despite years of Tory promises to bring it down, a study said yesterday.
It warned Boris Johnson that if his points-based immigration system allows a wave of mass immigration, then voters will turn against him.
The study from the Migration Watch UK think-tank said most recent polling found that 54 per cent think immigration has been too high over the past decade.
Only 5 per cent think it has been too low. And more than six in ten said they believe the Government has been mishandling immigration policies.
The analysis found that fears over the effects of large-scale immigration became a major concern after Tony Blair opened the doors to millions from both inside and outside the European Union.
Worries declined after David Cameron came to power in 2010 promising to cut immigration back to 1990s levels and subsided further after the 2016 Brexit referendum.
The report said: 'Most continue to have strong views about a perceived lack of effective immigration control.'
Harrowing images of children wearing lifevests being picked up by the Border Force vessel Hunter after being brought into Dover, Kent, on a small boat were released this week.
Kent county council has seen more than 500 unaccompanied child migrants, 23 of which came in on Thursday alone.
Council leader Roger Gough told The Times: 'Numbers started picking up last year with young people coming through in lorries. Then with the shutdown and disruption to freight channels, there was much more reliance on boats.
'We do not want a situation when there are adults in a setting with children and young people.
Home Secretary Priti Patel last night Tweeted: The number of illegal small boat crossings is appalling and unacceptably high.
'The figures are shameful. France and other EU states are safe countries. Genuine refugees should claim asylum there, not risk their lives and break the law by coming to the UK.
'I am working to make this route unviable. This involves: Stopping the boats leaving France in the first place and intercepting boats and returning those attempting to make a crossing.
'This is complex to do and we face serious legislative, legal and operational barriers.'
But former Border Force chief Tony Smith said extra resources may not solve the problem as the Navy would 'be in the same boat as Border Force in terms of policy. The only powers we have are search and rescue and that is what we have been doing'.
He told BBC Radio 4's Today programme that dangerous crossings of the Channel by boat will continue without an agreement with the French to return migrants.
He said smugglers are exploiting a 'loophole' in the law of the sea which obliges vessels to rescue people once they enter the waters of their jurisdiction.
'I think it can be overcome by bilateral agreements, we've done that before with the French.
'Once you're on the waterways the law of the sea kicks in and we haven't, without a bilateral agreement on instant returns or joint patrols with the French, which would enable us to safely return them to France to be processed, we're going to see I'm afraid continual numbers of this.
'And we need to find a way of breaking this circle and stopping the pull factor which is fuelling the smuggling supply chains.'
A tiny baby was spotted on Thursday morning arriving in Dover with its family after crossing the Channel in a dinghy - carried in what appears to be a gym bag
Former Royal Navy officer Rear Admiral Chris Parry said 'innovative solutions' like using unemployed passenger liners to re-route migrants are needed.
He said: 'We don't have to take them back to dry land. There's any number of unemployed passenger liners on the south coast at the moment, they could actually be taken there for processing for medical assessment and then onward routing either back to France or to the United Kingdom.
'I think people need to understand that the old ways are just not cutting it at the moment and we need to apply innovative solutions.'
But Mr Smith said: 'Once they are under our jurisdiction we will immediately face asylum claims.
'Without that agreement from the French to actually interdict people on the high seas and take them back to France the message is getting back to the migrants and to the smugglers that this is the way in and that does create a huge pull factor.
'We could see something very similar to what we saw in the Mediterranean three or four years ago where the word will get out that all you need to do is get out on to the English Channel, you will be brought into the UK and it's very unlikely you'll be returned.'