The Catholic bishops of England and Wales have decided that because not enough people are coming to Mass on Holy Days of Obligation, feasts including the Ascension should be celebrated on the following Sunday. This is cowardly. What they ought to be doing is encouraging people to attend. When I was working, Holy Days of Obligation were an opportunity to take part in the life of the Catholic community where I worked and not just the one where I live.
Anyhow, here is the Introit for the Mass of the day.