Previous administrations of Arun District Council failed to keep the Local Plan up-to-date, which has allowed developers to have free rein in Angmering. However, there is hope, as explained in the Friends of The Earth guide ‘The English Planning System: An overview‘-

“Presumption in favour of Sustainable Development (paragraph 11, NPPF 2019). Where a planning authority cannot demonstrate a five-year housing land supply, or housing delivery falls substantially below the requirement, a so-called “presumption in favour of sustainable development” applies. This allows developers to put in applications contrary to the Local Plan but which the local authority may find hard to refuse unless they can prove protected areas or assets provide a “clear reason for refusal”, or the benefits of the proposed scheme are “significant and demonstrably outweighed” by the impacts when assessed against other policies of the NPPF.“ (NPPF = National Planning Policy Framework)

Whilst both are considered out-of-date, both the Arun Local Plan and Angmering Neighbourhood Plan do still carry some weight, so are worth referencing in your objections.