Learn Two Words: Ditch and Last-ditch

Can you figure out the meaning of "last-ditch" in the following headline? Do you know its relation with the word "ditch"?

US lawmakers begin last-ditch effort on debt ceiling
http://www.reuters.com/article/2013/10/16/us-usa-fiscal-idUSBRE98N11220131016

Surfer_Diver
2013.10.16