Refer to figure.
Under the latest Standardised European Rules of the Air (SERA), in the event of lost comms, there is a new squawk code:

VFR flight: Squawk 7600 (as before)

IFR flight and opt to continue flight / no diversion: Squawk 7600 and maintain your last assigned level and speed for 20 minutes

• IFR flights are to maintain the last assigned speed and level for a period of 20 minutes following a radio communication failure before taking further action. This replaces the old "seven-minute rule" and applies to all IFR flights, including those in radar-controlled airspace. This gives ATC more time to identify the aircraft's position and protect it's track.

IFR flight in VMC and opt to divert to the nearest suitable airport instead of continuing the flight: Squawk 7601. This is a new code, intended to give ATC clarity that you intend to land visually.

Note: In the UK CAA exams, this squawk remains 7600.

ICAO Doc 4444
15.3 AIR-GROUND COMMUNICATIONS FAILURE

15.3.2 As soon as it is known that two-way communication has failed, action shall be taken to ascertain whether the aircraft is able to receive transmissions from the air traffic control unit by requesting it to execute a specified manoeuvre which can be observed by an ATS surveillance system or to transmit, if possible, a specified signal in order to indicate acknowledgement.

15.3.3 If the aircraft fails to indicate that it is able to receive and acknowledge transmissions, separation shall be maintained between the aircraft having the communication failure and other aircraft, based on the assumption that the aircraft will:

a) if in visual meteorological conditions:

1) continue to fly in visual meteorological conditions;

2) land at the nearest suitable aerodrome; and

3) report its arrival by the most expeditious means to the appropriate air traffic control unit;