My 8 year old DS has been writing in cursive for the last couple of years. He is in Year 3 and about to get his pen licence. I don't know what the expectation is but they are handing out pen licences in his year so assume they expect that by Year 3, age 8, they can write legibly using cursive handwriting but this is just a guess. I don't know what the national curriculum says about handwriting.
The "working towards expected standard" for year 6 says "producing legible joined handwriting" The "expected standard" says maintaining legibility, fluency and speed in handwriting through choosing whether or not to join specific letters.
There is no handwriting statement for working at greater depth.