UK Prime Minister David Cameron has called upon the European Union to reform its open immigration in order for Great Britain to remain in the group, calling for a new policy that requires migrants to wait four years before receiving specific benefits.

The prime minister has labeled this as the primary platform for the grounds in which the UK would keep its membership after a 2017 referendum.

Cameron said he doesn’t want to keep handing out tax and welfare benefits to migrants in the UK. His “emergency brake” idea of pulling the plug on EU movement, which has been touted frequently in recent months, hasn’t particularly won too many fans outside or within the UK. These new reforms are part of efforts to reduce incentives for potential UK immigration.

In Berlin, German Chancellor Angela Merkel stated the “emergency brake” idea, or even setting caps on migration, compromises the basic identity of the European Union’s freedom-of-movement policy.

Merkel even threatened that she would rather see the UK leave the EU rather than amend the free-movement principle.

Cameron’s efforts to deter migrants from coming to the UK by disallowing tax or child benefits, as well as access to social housing for migrants’ first four years, met a slightly warmer German response. Yet, it still leaves some controversy.

Germany is an economic heavyweight alongside the UK, and a rift between the two would undoubtedly result in a weakening of the EU. London Mayor Boris Johnson has also expressed discontent with the idea of closing Britain’s doors to immigration.

Johnson called the potential policy “nuts,” especially for London’s cosmopolitan population, in which 40 percent are born outside of the UK. The effect that makes on the economy is clear.

From that standpoint, reducing immigration would drastically affect London and the whole of the UK. It especially endangers London’s reputation as a leading global city. According to the Globalization and World Cities Research Network, London is classified as an “Alpha++,” city with an expansive global economy, leading the world. The only other city with this rank is New York City.

Sarah Sands, a journalist for the London Evening Standard, wrote that curbing immigration only allows London’s reputation to fall, allowing other cities such as Delhi or Hong Kong to take its position. In other words, the status is London’s to lose.

But what are some immigration-workforce numbers?

The University of Oxford’s Migration Observatory 2014 “Labour Market Overview,” foreign-born, or migrant, employment rapidly outpaced “lower-skilled” occupations by native-born. Nearly 44 percent of elementary factory work and 39 percent housekeeping and cleaning jobs were held by migrants.

These are low-skilled jobs with little to no career ladders. Native-born British aren’t striving to hold these types of positions, because they have access to education.

The fact of the matter, especially in terms of EU migrants with freedom of movement, is that these foreign-born workers seek temporary stays to receive and save work wages that are otherwise unattainable in their home economies (think Greece or Spain). Their plans are almost always to return home with money saved, being spent by their families, effectively bolstering their economies.

Considering all this, immigration seems like more of a reason for the UK to stay in the European Union than to leave.