Lost acceleration on road

[JRTOxf]

Last night I was driving at about 60mph in my 2007 Toyota yaris turbo diesel. All of the sudden the car started to gradually slow down despite keeping foot on the accelerator. There was no engine light on while this happened or any noise. I pulled over and turned the car off and it started back up ok and I was able to drive home as normal. 

Does anyone have any clue what this might be caused by? I'm taking it to a local garage on Monday.

Thanks!

[Dougie150]

Could be the fuel filter. When it first happened in mine it was when accelerating away after a roundabout, but like yours, started up fine again afterwards. The problem became more and more frequent until I changed the filter, after which it was fine.