Our shul sporadically gets people who come into the shul in the middle of the Shacharit minyan to ask for tzedaka. I think this is improper as it disrupts people's kavanah when they individually approach every person and ask for money.
Halachically, are they allowed to interrupt the minyan to ask people for tzedaka? Are there certain parts of the davening where they are allowed to interrupt vs. other times when they are not allowed to do so? Keep in mind that I stated that these people ask every individual, and some people may be at different points in the davening than the rest of the minyan. It doesn't seem that these collectors care where someone is up to.