Former PKR vice-president Rafizi Ramli has urged Khairy Jamaluddin to remain with Umno in order to forge a credible opposition.

In an open letter to Khairy, Rafizi said that a country without a strong opposition would be prone to abuses and Malaysia has experienced this over six decades.

"The next few days, weeks and months might be difficult for you, my brother, and for your comrades who are sincere in helping the people through Umno.

"Have faith that if you, my brother, were driven by service and the interest of the rakyat, the (defections from) Umno will only strengthen the party," wrote Rafizi.

Rafizi said many youths looked up to Khairy as the person who could make Malaysia better and bring forth a better future.

"Because of this, you must remain in Umno and continue to speak up so that Umno can be an effective opposition party," wrote Rafizi.

In response, Khairy jokingly wrote on Twitter that Rafizi was being a bit of a "diva" and that he should discuss such matters over lunch instead of penning an open letter.

Lain kali bisik la masa lunch. Diva betul open letter ni. 😝 — Khairy Jamaluddin (@Khairykj) December 14, 2018

Since the May 9 elections, a steady stream of lawmakers from Umno has been making its way out of the party. Currently, Umno has 38 MPs, down from 54.

More are expected to leave Umno in the coming days, primarily over dissatisfaction with Umno president Ahmad Zahid Hamidi.

