NEW Survation MRP: Labour on Course to Win 484 seats.
The Conservatives and Liberal Democrats are in a close race to form the official opposition.
Probabilistic seat count:
LAB 484
CON 64
LD 61
SNP 10
RFM 7
PC 3
GRN 3
34,558 interviews conducted online and on the telephone
Professor Paula Surridge of Bristol Uni says you should take this one seriously as all the modelling has been done by Chris Hanratty who did all the constituency-level breakdowns after the referendum.
The Ministerial and Salaries Act 1975 says it will be determined by the Speaker: www.legislation.gov.uk/ukpga/1975/27
But in practice, they may well balance the OO privileges (PMQs etc.) between the main opposition parties.