Lost P45

I'm starting a new job near the end of this month, but the company I left last month has had a fire in their accounts dept. I probably won't get a P45 from them anytime soon or ever. My question is will my emergency tax deductions stop at the end of this tax year (5th April) or will I be charged emergency tax into the next tax year as well? I would have thought as the new tax year starts soon my new workplace will know exactly what my tax status is beginning from April 6th.