Honestly, when Barcelona works hard enough, they will be able to beat Real Madrid, but for now I think they shouldn't have too many illusions about winning the League, yes, they are winning the League, it's because Real Madrid has allowed them to, and for now Real Madrid things are going very well in the UCL, which is something very big, for now the League is something that Real Madrid can once again take first place in the table, Barcelona have to focus more of their energies on the Europa League to see if they enter back to the UCL season, but they have it very strong because Man United, despite the fact that their spirits are very low because of CR7, I think they can come to play with everything.
Man United want to get back to the UCL no matter what, and the only thing on their mind is to have a lot of wins, this is where they need to focus a lot more.
What do you mean by "Real Madrid allowed them". Barcelona has been playing well so have Real Madrid. So for Barcelona to be top of the table it's because they work hard for it because Madrid is not giving them an easy run. Barcelona only got knocked out of the ucl because of injury and some bad tactics.
To me they have a better chance winning the league than the Europa. They play well in their league matches. They've won 12, drawn 1 and lost 1 out of 14 matches, that's pretty impressive. The difference between them and Real Madrid is that Madrid have draw 2 matches.
I do not think that Real Madrid really "allowed" anyone to be the first, they are playing well, they haven't lost or got a tie that commonly, they are playing well, the difference is that Barcelona is playing even better.
This is why I believe that we are going to end up seeing Barcelona win the title this year. On the other hand, if Barcelona still goes on to finals and win Europa cup, while Real Madrid somehow manages to lose both domestic cup and UCL at the same time, then we are going to see Real focus only to league, while Barcelona focusing on many other competitions and there could be some trouble there for sure, which will create a trouble for them.