Pushing the button once will energize the relay. Pushing the same button a second time will de-energize the relay. Any simple momentary action push-to-make switch will do.
I've drawn the circuit with a single pole relay. But you can use a multi-pole relay if it suits your application. The circuit will work at anything from 5 to 15-volts. All you need do is select a relay with a coil voltage that suits your supply.