Can you submit the same grant proposal to two different funding organizations?
You can propose for the same topic/ideas. But the EU and UK application process (even applications within the same &quot;country&quot;) are different and they look for different things for you to submit. So you can and should reuse old proposals (as no one has the time to make completely new proposals for every submission) as a &quot;base&quot; but they do need to be tailored for each submission. For instance the relative amount of space you have to write about method/novelty/timeliness/impact etc as well as practical things like page limits, page format, supporting documentation etc.
Given most proposals are also for different lengths of time/number of people proposals gain differences even if they cover the same area.
There can be limits about whether you can have multiple applications at the same time, but applications will be explicit about the limits in the supporting documentation. If your not sure ask your university research grants team as they know the details inside and out.