CPI(M) seems to be feeling bitter about its allies like BSP and JD(S) switching sides to the UPA after the Third Front's electoral debacle, with a senior party leader saying the post-poll developments have proved that the "cut and paste" alliance was a mistake.

"You are right about BSP, JD(S) and TRS and that is precisely the point that I am making, our decision is that it was neither credible nor viable and this (deserting the pre-poll alliance) only confirmed that," CPI(M) Politburo member Sitaram Yechury has said.