In a nutshell, the unhappiness with federation comes from a perception it has not delivered on two main promises made in 1962 – high levels of autonomy and economic development.

In the first area, the federal government has stripped away a lot of local powers in Sabah and Sarawak in the last 57 years. On top of that, the federal authorities have tried to impose the same toxic racial and religious politics found in Malaya (also known as West Malaysia) to the eastern states.

East Malaysia is much more ethnically and religiously diverse compared to the western part of the country. For example, the Malay population is a minority in both Sabah and Sarawak; in fact, no ethnic group constitutes more than 40 per cent in either state. As a result, political Islam has not taken root there.

In fact, one of the defining features of East Malaysia is intermarriage among the different ethnic and religious groups.

The divide between Muslims and non-Muslims is reasonably insignificant – a marked difference from the often suspicious attitude Islamic leaders have towards non-Muslims in Kuala Lumpur.

In terms of economic development, Sabah remains one of the poorest states in Malaysia. And the infrastructure in both Sabah and Sarawak is vastly underdeveloped compared to the west of Malaysia.

To add insult to injury, more than half of Malaysia’s oil and gas production comes from Sabah and Sarawak.

The common joke is that all the iconic infrastructure in Peninsular Malaysia, such as the Petronas Towers, Penang Bridge and Kuala Lumpur international airport, was built with money from East Malaysia.

Britain’s hand in the federation

In recent times, one of the biggest grievances in East Malaysia comes from the process of decolonisation administered by the British after WWII.

There is clear, documented evidence that back in 1962, the colonial office in London used its powers and influence to get the local leaders in Sabah and Sarawak to agree to the formation of Malaysia.

Activists in East Malaysia say if the British had not supported the formation of the federation, it was highly unlikely local leaders would have agreed to it. Many would have instead preferred independence or a federation consisting of Sabah, Sarawak and Brunei (which gained independence from Britain much later, in 1984).

What Sabah and Sarawak want

All these historical grievances have led to a growing movement in Sabah and Sarawak advocating for secession from the federation.

With elections upcoming in both states, all local politicians – including those serving in the federal government – are now claiming to be MA63 nationalists trying to keep “Malaya out” of Sabah and Sarawak.

Social media is one key reason the secessionist movement has taken off in East Malaysia. It is now much easier for advocates to organise and magnify their grievances.

Girl studying atop tree inadvertently impacts federal power in Malaysia

What the Sabah and Sarawak people want, at the very least, is a constitutional amendment to recognise the special autonomy of both states. But a significant minority argues the whole federation has failed, and thus secession is the only way forward.

Currently, the secessionist groups pose no real threat to the federation. But if enough people buy the secession argument in the future, public sentiment may be too strong for the national leaders to ignore.

How should the federal government respond?

There are basically two options available to the federal government.

The first is the ostensibly easy option – the political route. This would require the federal government to recognise the historical grievances and try to resolve them.

However, this is not as simple as it seems. The government is reluctant to grant real autonomy to the two states, worried this will end up weakening federal powers in the other 11 states of the federation.

There was an attempt to reword the Constitution last year to symbolically recognise the special status of both states, but it failed.

This is the only way to keep the federation together, however. The federal leaders need to agree to recognise the special status of Sabah and Sarawak and grant them wide autonomy in the Constitution, as envisaged in the 1963 Malaysia Agreement.

Why the Philippines is reviving its Sabah dispute with Malaysia

The second option for the government is to play a wait-and-see game. Politically, this is dangerous, as the final outcome could very well be secession.

By way of comparison, the push for independence in Catalonia was similarly based on historical grievances that mushroomed into a mainstream political movement and eventually an independence referendum – declared illegal by Spain’s constitutional court.

At the very least, what is happening on the ground in East Malaysia suggests the decolonisation process in Southeast Asia is not yet complete. This colonial legacy is not merely history, but is clearly reflected in the present reality.

Professor James Chin is Director of the Asia Institute, University of Tasmania. This comment was first published on The Conversation.