I work for a charitable organisation. I am currently coming to the end of my one-year fixed term contract. I have been working on a project that was funded for one year. However, the organisation has now gained additional funding through another funder to continue for a number of additional years. I am just wondering if legally the organisation have to re-advertise and go through the recruitment process again to fill the positions under the new funding contract or if our current employment contracts could be extended without having to advertise etc.
I presume from your message that the two funding streams are for the same work and overlap in terms of their start and end dates.
Your employer is not legally obliged to advertise the role and go through the recruitment process. They can simply agree to extend your current contract and this should be done in writing.
However, the charity may decide to advertise the role in order to avoid any potential argument that the process has not been transparent, fair and is potentially discriminatory because it prevents others from applying for the role which may disproportionately affect a particular group of individuals, such as men. Advertising the role might also be a requirement of the funding provider, or of their own internal processes. Furthermore, they might decide to run a recruitment process if the role going forward is different to your existing one and/or they bring your employment to an end for a legitimate reason (such as conduct or ability to do the job).
If your employer does advertise the role, they should inform you of the vacancy and give you the chance to apply for it, although they do not have to give you the job simply because you are currently doing it.