Central London is set to be a no-go area for traffic this afternoon as a major march makes its way from Clerkenwell to Trafalgar Square.
Transport for London advised drivers to "expect delays" during the march from 1pm until 5pm.
The Metropolitan police said roads will close as the parade passes through and reopen once marchers have passed through.
All Tube lines serving the area of the march were functioning with a good service during the morning.
The London May Day march will leave Clerkenwell Green at 1pm, before passing down the Clerkenwell Road onto Theobalds Road.
May Day March & Rally TODAY, 1pm-5pm - Clerkenwell Green to Trafalgar Sq, via High Holborn, Kingsway, Aldwych & Strand. Expect delays.— TfL Traffic News (@TfLTrafficNews) May 1, 2017
It will then move past Red Lion Square, past Holborn Station via Kingsway towards Aldwych.
The last leg of the journey will take it down the Strand towards the main rally.
A rally in Trafalgar Square will start at around 2.30pm, where marchers will be addressed by Labour shadow chancellor John McDonnell as well as a range of trade union representatives. They will be protesting against austerity and anti-trade union laws.
Marches takes place around the world on May Day to mark International Workers’ Day, known as Labour Day in some countries.