ECHp advice!

my daughter attends nursery 5 hours a week (she is 3) because this is all the nursery can safely cope with and offer 1:1 support for until the EHCP is done. She has had 1.5 years of portage therapy, two intensive rounds of targets, 3 rounds of IEPs and needs still remain severe. The LA have just refused to do EHC needs assessment due to not spending enough time at nursery! that was literally there only reasoning.. But that puts me in a loop as the nursery cannot safely have her more right now as she requires an adult with her 100% of the time. The nursery hit back to the LA saying without the echp support my daughter simply cannot safely access the nursery environment or curriculum. The nursery have told me to let them deal with it however I’m aware I only have a certain time frame to appeal.. if you have any advice I’d be so grateful. Thankyou!