Actually, the pope does govern the matter of this permission since he is the author of the Catholic Church’s code of Canon Law. Through the code, he does set conditions for when non Catholic Christians who belong to this ecclesiastical community can lawfully receive certain sacraments.
Canon 844 considers when members of the Eastern Orthodox Churches or other Christians may receive the sacraments of penance, Eucharist, and anointing of the sick from a Catholic minister according to the law of the Catholic Church…
The situation of Anglicans, other Christians not having full communion with the Catholic Church, would be treated in canon 844 §4.
“If the danger of death is present or if, in the judgment of the diocesan bishop or conference of bishops, some other grave necessity urges it, Catholic ministers administer these same sacraments licitly also to other Christians not having full communion with the Catholic Church, who cannot approach a minister of their own community and who seek such on their own accord, provided that they manifest Catholic faith in respect to these sacraments and are properly disposed.”
Note all of the conditions must be present. They boil down to two possibilities.
There is danger of death and the Anglican cannot approach an Anglican minister, seeks one of these sacraments from a Catholic minister on his or her accord, believes what Catholics believe about the sacrament, and is properly disposed.
The Catholic diocesan bishop or the conference of Catholic bishops determines that a grave necessity urges it, the Anglican cannot approach an Anglican minister, seeks one of these sacraments from a Catholic minister on his or her accord, believes what Catholics believe about the sacrament, and is properly disposed.
Another part of that same canon, §5, permits the diocesan bishop or the conference to issue general norms on the point. Since you live in the England, you’d have to inquire whether or not the local Catholic bishop or the UK conference of Catholic bishops had issued such norms and determined what constitutes a grave necessity.
So while a priest could administer Holy Communion to an Anglican in danger of death with the other conditions being met, he could not do so lawfully outside of that unless the diocesan bishop or conference of Catholic bishops had issued norms permitting him to do so.