I do not know much about Virgin Media (and its American owners) apart from the competitive services it offers in the UK. I am also aware of the services that Telefonica/O2 offers both in the UK and elsewhere.
Regarding the stocks, I can only comment on Telefonica, hence here is my point of view on the stock:
I have been following Telefonica for some time and as you can see for yourself its price has been falling for over 10 years. It has offered good dividends (though quite often as shares not cash) however even if you include the dividends since 2010, if you would have invested then the break even price would be around 10 euros
without considering dividend taxes.
I also think that Eurozone stocks will go down again before they go up again, this particularly applies to Telefonica which has recovered very little from the Coronavirus impact on its stock price, it was over 6 euros prior to COVID-19 and now it is around 4.30 euros, quite close to its minimum price during this crisis which was around 3.70 euros.
The main factor that analysts have penalised it on is its high debt. Over the last few years it has decreased it by carrying out significant disinvestments, which also leads to lower revenue. It is believed to have put its south and central american businesses (except Brazil) for sale, however I do not think that this represents a large portion of its EBITDA and it does not seem like it will manage to sell it during the COVID-19 crisis, it will have to wait.
Also, it has confirmed its 0.40 euro dividend for this year (in 2 payments, half in June/July and half in December), however I think that it will be mainly given out in the form of shares with its associated share dilution.
As I understand it the Virgen+O2 agreement will not be implemented until 2021, so the short term impact of the merger will be limited. Also, it will need to be approved by the relevant competition authorities, whether European or British (or both).
As such, and considering its downward trend I think that an interesting price to invest at would be around 2.50 (maybe a bit higher if the IBEX35 does not fall much more). I think that from such a price and if it manages to get into the digital/cloud based market the share price could grow alot.
Obviously, all of this is just my own opinion .