The Ministry of Justice looks after the administration of the relationship
The relationship between the UK and crown dependencies needs to be clarified, according to a report by the UK's Justice Committee.
It investigated the relationship and its administration, which is carried out by the Ministry of Justice.
The report said it supported the unique constitutional position and independence of the three dependencies; Guernsey, Jersey and the Isle of Man.
However, it said more needed to be done to foster mutual understanding.
It found the crown dependencies were democratic, self-governing communities with free media and open debate.
The report said the Ministry of Justice carried a considerable workload and should "reappraise the priorities for its crown dependencies work; focus more on its constitutional duties; and spend less time on issues for which it is not formally responsible".
It suggested "the Ministry of Justice should give clearer guidance to other Whitehall departments who conduct business affecting the crown dependencies".
It said the interests of the crown dependencies needed to be considered routinely in all areas of UK policy-making and legislation likely to affect them and that departments needed to be made aware of the constitutional position of the islands, their essential independence from the UK and their independence from each other.
It suggested that secondments of officials between the UK and the islands' governments would help increase understanding.
Sir Alan Beith, chairman of the Justice Committee, told BBC Guernsey the dependencies were often overlooked.
He said: "Two dramatic examples of that are the reciprocal health agreement, where the implications of changing that were not fully understood, and even more the UK borders bill, which suddenly landed people in Guernsey thinking they were not going to be treated as UK citizens with the right to travel to England without a passport and, in a last minute rush of administration, was thankfully withdrawn.
"For that to happen demonstrates a lack of understanding of the historic relationship."
The chief ministers of all three dependencies welcomed the recommendations.
Crown's responsibilities to islands
Ultimate responsibility for "good government"
Ratification of legislation by Royal Assent
Ensuring the islands meet international obligations
Jersey's Chief Minister Terry Le Sueur said: "I am pleased the committee's report has reflected the long standing status of the Crown Dependencies as democratic, self-governing communities with free media and open debate."
Tony Brown, the Isle of Man Chief Minister, said: "It is particularly helpful that the committee stated, in strong terms, that the UK Government has a duty to represent our interests on the international stage, even when our interests are not the same."
Guernsey's Chief Minister Lyndon Trott said: "The report will provide the ideal platform to discuss ways to develop the way the relationship is managed with the minister responsible following the UK general election. Through the strong working relationship we already have with the UK Government I look forward to developing our and the committee's suggestions."
The Justice Committee was appointed by the House of Commons to examine the expenditure, administration and policy of the Ministry of Justice and its associated public bodies.
This was the second inquiry into the relationship, which followed on from the inquiry into the representation of the crown dependencies during the Icelandic banking crisis.