Am I subject to an English language requirement?

No. The English language requirement was removed by the SRA in March 2015 so candidates are not required to take any English language test such as IELTS or TOEFL before taking the QLTS assessments or as a condition to be admitted as a solicitor. 

However, you should ensure that your standard of written, spoken, reading, and listening English is appropriate for the assessment otherwise you are unlikely to pass it.