The launch of a new £5.7 billion fleet of high-speed trains descended into farce as the first journey was overcrowded, hit by delays and faulty air conditioning - all while the Transport Secretary was on board.

The new fleet was hailed by Chris Grayling before the maiden journey departed as "a fantastic service" but he swiftly found himself trapped on a train packed with frustrated commuters.

The fleet launched with great fanfare but the first journey was largely overshadowed as water poured from the air conditioning and the train was delayed by approximately 40 minutes.

The new Hitachi-built Intercity Express train had been due to leave Bristol Temple Meads for London Paddington at 6am sharp but the Great Western Railway service did not depart until 6.25am because of unspecified 'technical issues'.

Passengers were forced to stand despite claims that capacity on the new trains had been increased by 20 per cent.