Cameron has championed the introduction of an upper annual limit of immigration and an increase in the minimum age for foreign nationals to join spouses in the UK to 21. According to José Manuel Barroso, the President of the European Commission, Cameron's immigration policy would be illegal under EU law. The UK High Court also declared the minimum age for foreign spouses to be unlawful. He has called for the introduction of a British Border Control police force, quotas for asylum seekers and all asylum claims to be assessed in overseas centres. If necessary, the party under his leadership would "tear up its commitments under the 1951 UN Convention on Refugees to get its way."