Morgan’s petition calls on locals to express their “strong opposition to proposals to close Oswestry Post Office” and received more than 1,000 signatures in the first 24 hours.
The Liberal Democrat said the branch on Willow Street was the only place in the Oswestry area which offered the full range of services to small businesses.
She rose the issue in the House of Commons and Gareth Thomas, Parliamentary Under Secretary of State for Services, Small Business and Exports told her that while no final decision had been taken, the Post Office was pushing ahead with consultation.
The government-owned Post Office has 11,500 branches across the UK, most of which are franchises, with 115 Crown Post Offices.
Services provided at the threatened Crown Post Offices may be moved into other stores, such as WH Smith, if they are closed.
The Post Office said it had been forced to consider the closures because it faced a host of challenges, such as stiff competition from rival parcel operators like Evri and fewer people sending letters, with revenues for its branches being hit as a result.