vindictive

vin·dic·tive

adj.

1. Disposed to seek revenge; revengeful.

2. Marked by or resulting from a desire to hurt; spiteful.

Incidentally, officially, Kejriwal is still an IRS employee as the department has not accepted his resignation tendered in 2006.

The I-T department maintains that Kejriwal violated bond conditions and his resignation, will be accepted only once the dues are cleared.
Team Anna member Justice Santosh Hegde says the timing seems vindictive.