Members of Occupy Wall Street chained open the subway gates at some 20 stations yesterday, in an apparent attempt to give straphangers a free ride and draw attention to their plans for a general workers’ strike next month.

The protesters claimed they had help executing their scheme from “rank- and-file” subway workers in the Transport Workers Union and Amalgamated Transit Union

Both of those unions represent MTA employees.

A spokesman for the TWU — which is locked in contract talks with the MTA — said the union would never sanction that type of action because workers caught could lose their job.