Lectureship application teaching reference?
For Russell Group? Research is king - this is not a teaching post, it's a research position (UK Russell Group lecturer is broadly equivalent to an assistant prof at a US R1 - the job titles are different).

Your CV should mention teaching experience, certainly, but your reference letters should be talking about your research skills, and your likelihood of securing funding. What are your REF 4* papers, what funding do you have – those are what matters. 

(Source: I'm an SL at a Russell Group Uni, recently on interview panel for lecturer posts)