I know some sections of the Tamil population don't see 13A as the solution to the national question. They have a valid concern, and I understand it. 13A has enough loopholes for the Sri Lankan government to give power with one hand and take it back with the other hand. In the absence of state government support, 13A is utterly useless. For example, the democratically elected provincial council has no authority over financial or administrative matters. The governor who is appointed by the president has control over both administration and finance.
The Chief Minister and other ministers can help or give advice to the governor but he is not required to act on it. Through the governor, all financial and administrative powers are once again placed in the hands of the Sri Lankan government. During C.V. Wigneswaran's tenure as Northern Chief minister, 13A was partly implemented (13A minus land and police), but the governor never allowed him to establish the chief minister fund, despite similar funds being established in three provincial councils (Southern, Sabaragamuwa and Uva). Based on past experience Tamils feel, even if 13A is fully implemented the provinces where the Sinhalese are the majority will enjoy the fruits of 13A while Tamils would still be treated differently by the Sri Lankan government.
Furthermore, even though the provincial council will be granted ownership rights to state land in the province if 13A is implemented, all issues related to land still fall under the President's jurisdiction. So the provincial council cannot distribute land to its people. So, people from other provinces can be allocated land to settle without the permission of the provincial council. The Tamil people are not against Sinhalese individuals coming and settling from the south by purchasing land or resettling Sinhalese who left the northern province due to war. They are only concerned that granting land without the consent of the provincial government can lead to mass colonization of Sinhalese from the south. This will change the demographic composition of the North. The Tamil people say the same thing happened in the Eastern province.
According to the 1946 Census Tamils are 48.75% of the eastern province and the Sinhalese population is just 8.40%. Then mass colonisation of Sinhalese happened through irrigation development schemes like Maduru Oya, Mahaveli and etc. For example, if you take the Maduru Oya project systems H and C, 90% of the settlers were Sinhala and 10% Muslim. There were no Tamils, even though the land was in the Eastern Province. It was a UNP policy laid down by JR and energetically implemented by Gamini. These kinds of acts reduced the Tamil population distribution in the East. According to the 2012 census, Sinhalese make up 23.15% (nearly 300% disproportionate growth compared to 1946) and Tamils dropped to 39% in the Eastern Province.
These are all genuine concerns, It is indeed true that the provincial council can only function if every Sri Lankan government that comes to power hereafter is sincere in its commitment to devout power. As long as every president allows land allocation and other financial proposals of the provincial council, as long as every president instruct the governor to implement the decision taken by the democratically elected provincial council in the north and east, this model will work. But looking at past history it is highly doubtful.
But is there any other way around this? I can't see one at the moment. 13 plus (13A with these loopholes removed) will not get any parliamentary 2/3 majority. Even if it gets a majority in parliament there is a high possibility that some clauses will require a public referendum. Do you actually think more than 50% of the Sri Lankan population will vote in favour of that amendment? At this point, only the full implementation of 13A is possible. If the Sri Lankan government continues to disrupt provincial council activities without due regard to the rights of the Tamil-speaking people, we could always launch a peaceful, non-violent campaign of civil disobedience based on Gandhian principles.
A form of large-scale civil disobedience was successfully employed in January 1961 in the North and East against implementing Sinhala as the sole administrative language in the North and East. This led to the eventual passing of "The Tamil Language (Special Provisions) Regulation" which made Tamil the language of administration in the Northern and Eastern provinces. So there are things we can do even if the Sri Lankan government breaks its promise. Remember something is better than nothing. It is a long journey to peace and reconciliation. Let's begin by taking the first step.