Mortgage property - property affecting in road development

I have 100 sq yards property mortgaged to bank but now 20 sq yards is affecting in road widening, government issued notice to submit proper documents and make gift in favor of government. At the time when im mortgaging the property sq yard value is 50,000/- now the sq yard value is 70,000/-. I asked for NOC for 20 sq yards but bank is not accepting.please tell me possible ways other than release of property.