"There is a number of" versus "There are a number of" [duplicate]

Possible Duplicate:
A number of questions “has been” or “have been” asked?

There is a large number of labourers who want to migrate to Japan for work.

I type this sentence in a word processor, and it reports an error that "is" should be "are" (subject-verb agreement).

I doubt this is a valid error. Could anyone confirm this?

Solution 1:

This site has a good explanation about some of the subtleties of using collective nouns. In particular:

Note that "the number" is a singular collective noun. "The number of applicants is steadily increasing." "A number," on the other hand, is a plural form: "There are several students in the lobby. A number are here to see the president."

It's a peculiarity of "number" as a grouping noun. If you had said "group" instead, then the singular would have been correct:

There is a large group of labourers who want to migrate to Japan for work.

Solution 2:

It should be "are". The phrase "a large number of labourers", like "a lot of labourers" and "a dozen labourers", is a plural construction in English and takes the verb "are".