Home Schooling and Funding Legalities

Hi All,  I'm new here and looking for some specific advice.

My son has been having a terrible time at his primary school, and we are seeking a new placement for him. In the meantime, the deal is that he will remain on roll, and will attend for the final hour of each day to try and keep him engaged. He has an EHCP and full funding for a 1:1 key worker for each day. He's now in year one and since being at the school has barely ever made a full day. It is a disaster, there are just so many things wrong. 

Anyway, whilst we await a new placement, he will effectively be home schooled 90% of the time. I understand that the school still have a responsibility to ensure, and presumably fund, his education. We are now chasing budget as we will be teaching him, and we need resources as the school are providing nothing. The LA have gone away to look at this but we've heard nothing still. Does anyone have any experience of this and what are we legally entitled to? Should we be consulting an SEN lawyer to assert our rights/case? 

Many thanks in advance.