You absolutely have the right to decline vaginal examinations.
Some information for you:
Do I have to have a vaginal examination to assess whether I am in established labour?
No. You always have the right to decline any intervention, including vaginal examinations (VEs). If you have given your consent to a vaginal examination under pressure, for example, because you have been told your partner cannot join you until you are in established labour, your consent may not be valid and the healthcare professional could be legally liable if they proceed with the VE.
There are other ways for an experienced midwife to tell if you are in established labour (around 3-4cm dilated) and therefore ready to be admitted to the unit if that is your plan. If you are still in early labour, you should have the option of returning home with your partner. If there is any doubt about whether you are in established labour or not, you should be admitted to the birth centre or labour ward if there is room.
From www.birthrights.org.uk/2020/03/12/coronovirus-how-will-it-affect-my-rights-to-maternity-care/
And
It is important to know that while VEs are offered to almost every woman, and they are often seen as an essential part of labour, there is actually a lot of evidence to support women considering not having them at all - this will be discussed below.
www.aims.org.uk/information/item/vaginal-examinations-in-labour
When I gave birth to DC1, the midwife did very frequent vaginal examinations (which I don't even remember consenting to), even after my waters had broken, and after the birth I developed a uterine infection, which I don't think was a coincidence.
When planning my second birth, I decided that I didn't want any vaginal examinations unless I requested them... as it is, everything happened so fast that the midwife arrived when I was pushing, the closest she got to an examination was checking the baby's heartbeat on her way out (I didn't know they could do that!)