Ukip says rescuing migrants off Europe “may actually be making matters worse”, while the Tories want to “dissuade migrants from making these perilous and illegal journeys in the first place”.
Up to 400 migrants, including children, are feared drowned after a boat capsized off Libya on Tuesday, leaving only about 150 survivors.
Since Friday, 8,500 people have been rescued from the Mediterranean after trying to sail from the north African coast, according to the UN Refugee Agency.
The numbers are expected to climb rapidly, with EU border agency Frontex predicting that over 500,000 people are waiting to set sail from Libya over the summer, but migrants are likely to use other routes too.
This is the challenge facing Italy and other EU countries including the UK, which have proved prime destinations for migrants in the past.
Thousands of people are risking death to seek a better life, but the UK’s political parties have starkly different views on how to deal with migrants’ determination to reach Europe’s shores.
Read more: Lampedusa - why are so many migrants dying at sea?
Last year the UK Foreign Office said it would not support future search and rescue operations in order to prevent migrants from drowning in the Mediterranean sea.
It said such operations can encourage more people to attempt the perilous sea crossing, but offered support to a new European effort to enforce European border security.
Get the latest election updates - Channel 4 News live blog
The Green party stands out for its pledge to increase funding for rescue efforts, and to take more migrants inside UK borders.
But this is far from the Ukip position – the party is against rescue efforts, but maybe not for the reasons you would expect.
“Far from turning their backs on the great migration from north Africa, the EU’s current ‘rescue efforts’ may actually be making matters worse,” Steven Woolfe, Ukip’s migration spokesman, told Channel 4 News.
He says actions by Operation Triton, Europe’s Mediterranean border patrol, are intended “to prevent criticism of inaction in EU capitals”, but the operation actually “incentivises the people smuggling mafias to be bolder”.
“How close to the Libyan coast are the ships under the command of Operation Triton actually going to pick up migrants?” he adds.
“Several news reports indicate that they are making efforts to interdict the ships of the people traffickers so close to the coast that the criminals are actually firing on the EU’s forces to get their vessels back once they have been emptied of their migrant cargo and shipped to the EU mainland.”
The Conservatives, unsurprisingly, back current government policy to stand back from the growing crisis.
“We believe that the only sustainable means of addressing this issue is to take action to dissuade migrants from making these perilous and illegal journeys in the first place, enhance protection in refugees’ regions of origin, and combat the criminal gangs who place migrants’ lives at risk,” a spokesman told Channel 4 News.
“This is why we support the EU’s focus on action ‘upstream’ in countries of origin and transit.”
Read more: Lampedusa - redefining Italy's conscience on immigration
He added: “The government is working with other EU states to prevent the deaths of people crossing the Mediterranean through joint efforts under the EU’s Task Force Mediterranean, established following the Lampedusa tragedy in October 2013.”
The Tories’ coalition partners, the Liberal Democracts, take the same approach – a spokeswoman said the party supports “European co-operation”, and would “push for more effective EU measures to prevent the tragic loss of life for many crossing the Mediterranean”.
Nick Clegg’s tweet after this week’s disaster further served to back current government policy: “This reminds us of the importance of the UK aid budget to ending poverty so people do not have to take such risks in the future,” he said.
The Labour party also lines up behind a “comprehensive international approach” between the EU and north Africa, but deplores leaving charities like Medicins Sans Frontiere “to pick up the tragic pieces”, according to recent comments from shadow home secretary Yvette Cooper.
She said this week’s tragedy “shows how immoral and wrong it is for the government to argue that ‘search and rescue’ operations in the Mediterranean should be stopped in order to deter people from traveling”.
“More and more dangerous, overcrowded boats are coming across,” she added. “Leaving some people to drown in order to deter others is a shocking and inhumane approach, not worthy of Britain’s long history of helping those whose lives are at risk.”
But she has stopped short of committing any more money to help greater British participation.
In a stark comparison, Green party leader Natalie Bennett has called for “immediate action to prevent further tragedies”, saying Britain “should immediately pledge funding to help with the search and rescue operation in the Mediterranean”.
“We cannot simply stand by while hundreds of people drown in our continent’s seas,” she added. “The charities saving people’s lives in the Mediterranean must be properly resourced, and Britain must help with this.
“In the longer term we must push the EU into rebuilding an effective scheme to rescue migrants in the Mediterranean – we shouldn’t have to rely on the heroic work of charities to undertake this basic humanitarian task.”
The SNP did not respond to a request for comment.