With only 3 Wcf vacancies as it stands in London, it might be worthwhile to check out job ads in similar fields. The available vacancies can be split up into main categories like Enterprise Software and System Integration areas. If you're on familiar terms with fields like C#, .Net and ASP.NET, you're a shoo-in for vacancies like this.
Expert applicants are in luck, as many employers are now exclusively seeking Wcf professionals of a high calibre. Most employers use recruiters to find applicants in this area. Make sure to filter those from your Jobfeed if you'd rather not see the vacancies they posted. Use the region map at the top of the page to see where the offices are located.