Here is the official SW thread where we can discuss our applications for the 2015 recruitment cycle. I have put together a list below just to make things easier (going to keep this updated as applications open).

Bank of America Merrill Lynch:
http://campus.bankofamerica.com/get-started/Pre-Internships/?r=Europe, Middle East and Africa (Open Now)
Barclays:
http://joinus.barclays.com/emea/spring-programmes/
Credit Suisse:
https://www.credit-suisse.com/uk/en/careers/campus-recruiting/our-business/internship-programs-emea/outreach-programs.html (Open Now)
Deutsche Bank:
https://www.db.com/careers/content/en/spring_into_banking.html (Open Now)
Goldman Sachs:
http://www.goldmansachs.com/careers/students-and-graduates/our-programs/emea-programs/division-spring-internships.html (Open Now)
Citi:
https://www.citi.gtios.com/Vacancy/Search/PreLogonSearchPostedCriteria.asp (Open Now)
J.P. Morgan:
http://careers.jpmorgan.com/student/jpmorgan/careers/springweek (Open Now)
Morgan Stanley:
http://www.morganstanley.com/about/careers/programs/additionalinternship.html
UBS:
http://www.ubs.com/global/en/about_ubs/careers/graduate_and_intern/europe_middleeast_africa/ubs_insights.html (Open Now)
BNP Paribas:
http://graduates.bnpparibas.com/spring-insights/
HSBC:
http://www.hsbc.com/careers/students-and-graduates/programmes
ICAP:
http://www.icapcampusrecruitment.com/Programmes/Industry-Insight.aspx (Open Now)
Nomura:
http://www.nomura.com/europe/careers/insight_programs/explore-nomura-program.shtml (Open Now)
RBS:
https://www.rbsbankyoubuild.com/interns/spring-week (Open Now)
Rothschild:
http://www.rothschild.com/Careers/Spring_Programme/

There's also a helpful guide written on SW applications, absolutely worth a read before you start applying: http://canarywharfian.co.uk/threads/how-to-get-a-spring-week-part-i.63/