Why is DUP support so important to Theresa May and the Conservatives?

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The National
Why is DUP support so important to Theresa May and the Conservatives?

THERE are 639 MPs in the House of Commons who are considered active once the seven Sinn Fein MPs and four speakers and deputies who don’t vote are removed from the total of 650.

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The National
Why is DUP support so important to Theresa May and the Conservatives?