Bus drivers in London are taking part in a 24-hour strike over pay differences between the capital's 18 bus companies.

Members of the Unite union walked out at 00.00 GMT (5 February), leaving travel disruption for commuters.

Transport for London has said around 47% of its bus routes were running, but warned there would be disruption to services across the city and to night buses early on Friday morning.

Today's strike is the first of three as part of a long-running campaign for a single agreement covering pay, terms and conditions. The next are scheduled for 13 and 16 February.

Unite has said there is no collective pay deal between drivers, meaning that there are 80 different pay rates for drivers doing the same job as wages were negotiated depending on the company. The union said hourly rates can vary by more than £3.

Pete Kavanagh, London regional secretary of Unite, told BBC News: "We've got a two-tier workforce in which people coming into the industry in recent years never get to the top rate of pay. We've literally got hundreds of rates of pay and this has got to stop."

TfL has said the strike is "totally unnecessary" and that it will cause "significant" disruption. TfL's director of buses has claimed "levelling up" pay would cost around £100m a year, resulting in a "cut to bus services, an increase in fares, or both."

The bus companies likely to be affected are: Abellio (Abellio London and Abellio West London); Arriva (Arriva North and Arriva South); CT Plus (Hackney Community Transport); Go Ahead (Blue Triangle, Docklands, London General, London Central, Metrobus); London Sovereign; London United; Metroline (Metroline and Metroline West); Stagecoach (East London Bus & Coach Company, Selkent); and Tower Transit.

Bus services on Friday should operate as normal.

Unite has posted a graphic on Twitter explaining the bus strike:

Which bus services are running?

The bus services below are not affected by the strike, according to TfL. You can also click here to see if your bus is running, or follow @TfLBusAlerts on Twitter.

66 - Romford Station to Leytonstone bus station

142 - Watford Junction to Brent Cross Shopping Centre

160 - Catford to Sidcup Station

258 - Watford Junction to South Harrow Station

268 - Golders Green Station to Finchley Road

288 - Queensbury to Broadfields Estate

298 - Arnos Grove to Potters Bar

303 - Edgware Station to Colindale

305 - Edgware Station to Kingsbury Circle

340 - Edgware Station to Harrow Bus Station

346 - Upminster Station to Upminster Park Estate

370 - Romford to Lakeside Shopping Centre

375 - Romford Station to Passingford Bridge

404 - Coulsdon to Caterham-on-the-Hill

406 - Kingston to Epsom

411 - Kingston to West Molsey

418 - Kingston to Epsom

428 - Erith to Bluewater Shopping Centre

463 - Coulsdon South Station to Pollards Hill

465 - Kingston to Dorking

467 - Hook to Epsom

470 - Colliers Wood Station to Epsom

492 - Sidcup Station to Bluewater Shopping Centre

499 - Gallows Corner to Heath Park Estate

626 - Finchley Central Station to Potters Bar

628 - Kingsbury to Southgate Station

631 - Golders Green Station to Henrietta Barnett School

641 - West Molesey to Teddington School

642 - West Hendon Broadway/Edgware Station to London Academy

653 - Muswell Hill Broadway to Kingsbury

683 - Friern Barnet to Kingsbury

688 - Southgate Station to Kingsbury

B12 - Erith to Joydens Wood

B13 - Bexleyheath Shopping Centre to New Eltham Station

B15 - Bexleyheath Shopping Centre to Horn Park

E10 - Northolt to Ealing Broadway Station

H2 - Golders Green Station circular (via Hampstead Garden Suburb)

H3 - Golders Green Station to East Finchley, Hilltop

H18 - Harrow Bus Station circular (via Pinner & Wealdstone)

H19 - Harrow Bus Station circular (via Wealdstone & Pinner)

K5 - Ham to Morden Station

S1 - Banstead to Lavender Fields

S3 - Sutton Hospital to Malden Manor Station

X26 - West Croydon to Heathrow Airport

How long does it take to walk between tube stations?

A walking map - shared on social media with the hashtag #WalkLondon - is a good alternative for those wanting to avoid public transport.

How can you use Oyster cards, travel cards and tickets?

TfL has said the following ticket acceptance arrangements will apply during today's strike.

Bus & Tram Pass season ticket, 11-15 Zip Oyster photocard or 16+ Zip Oyster photocard with free bus & tram travel will be accepted on Tube, DLR and London Overground services on reasonable routes only. Passengers should show their Oyster card to a member of staff and ask to be let through the gates. Customers should not touch in or out as they will be charged a pay as you go, which will not be refunded.

Bus & Tram Pass season tickets will also be accepted on MBNA Thames Clippers RB1 River Bus service between 06:00-10:00 and 16:00-19:00.

Bus & Tram Pass season tickets will not be accepted on National Rail services or the Emirates Air Line.

One Day Bus & Tram Passes will not be accepted on any alternative services and refunds will not be given.

Pay as you go users will be charged the appropriate fare for the journey for the service(s) and zones used and these fares will not be refunded.