From Tier 2 to EEA national family member-work eligibility

Hi,
I am seeking some advice on employment change. I have been working in the UK under Tier 2 as I am a non-EEA national. I got married to an EEA national in the UK recently. I will apply a Residence Card using form EEA2 in a few months time due to pre-planned trips. Before I receive the resident card, if I wish to change employer may I do so without the new employer being a Tier 2 sponsor? Is the marriage certificate sufficient enough to prove my eligibility to work in the UK exercising the treaty rights, or I will have to wait until I receive the resident card then I can work without employer sponsorship? Thank you.

What the law states is that you can work under the conditions of a family member of an EEA partner exercising their treaty rights in the uk so officially you do not need.to get another tier 2 to move to a different employer.
HOWEVER if you put forward your existing passport / Visa / BRP it is unlikely an employer would accept that even with the marriage certificate etc. If they were to use the employer checking service prior to you submitting your EEA application you would show up as having no right to work other than for your existing employer.

If your prospective new employer is willing to take the risk that is up to them. If they seek legal advice they will be told you can be employed under EEA rules but the general view is they will expect you to prove you have at least applied under EEA.