Error with plugin in cfg file using nosetest

I have a file with the following lines:

suite = LazySuite(all_tests)
run(suite=suite, argv=['','-c', 'nose.cfg'] )

And I have this nose config file:

[nosetests]
stop=1
with-xunit=1
xunit-file=test.xml

And when I run the testsuite, the following message is showed:

Usage: TestSuite1.py [options]

TestSuite1.py: error: Error reading config file 'nose.cfg': no such option 'with-xunit'

Process finished with exit code 2

I don't know what is happening, because if I execute the xunit plugin in the cmd directly as argument, the script is executed without problems.

Any suggestion?