The 34-year-old saw his team surrender the Ashes after losing to England by an innings and 78 runs at Trent Bridge.

He averages only 16 from eight innings and Australia are 3-1 behind with one match left at The Oval on 20 August.

"I certainly don't want to jump ship and leave the boys now. I'll play the last Test, give it one last crack, but the time is right now," Clarke said.

Clarke made his Test debut in October 2004 and he has played 114 matches, scoring 8,628 runs at an average of 49.30.

This summer's Ashes defeat is the fourth he has endured playing in England.

He took over the Australia captaincy from Ricky Ponting in March 2011 and has presided over 46 matches, winning 23 and losing 16.

In January last year Australia whitewashed England 5-0 when Clarke scored two centuries and averaged 40.33 in the series, but since March 2014 the captain's last 18 innings have produced 388 runs.

Clarke, who stepped down from one-day internationals in March, revealed he had decided to retire from Test cricket on Friday evening.

"I felt my performances weren't as good as I wanted them to be," he said.

"The decision is never easy. I started playing this great game at six years of age. I'm 34. I wish I could play for another 30 years."

England captain Alastair Cook paid tribute to his Australian counterpart.

"To Michael from the England team - you were a fantastic player, fantastic leader," Cook said. "You should be remembered as a great captain."