The UK was downgraded in April this year to double-A plus as the chancellor continued to miss his targets on borrowing.
Although the economy has picked up since then it will be some time until the rating will be increased once more.
Until the national debt starts to fall as a percentage of GDP in a sustainable way, the triple-A rating is unlikely to be restored.
“Some of the adjustment that has gone on since then has been a pleasant surprise for everyone ... but one of the things we have said about getting triple-A ratings back is that it is going to take some time,” analyst James McCormack told Reuters.
“We probably need to see medium-term projections of debt-to-GDP coming down in a sustainable way over a period of time. So one quarter or six-months’ worth of data is generally not something we are going to change our rating view on.”
Last week the Office for Budget Responsibility said the debt to GDP ratio is likely to peak in 2015-16 at 80 per cent of GDP before gradually falling in the following years.
Meanwhile Fitch warned Eurozone governments they risk never recovering their pre-crisis ratings because they are failing to cut their debts.
The sovereigns have struggled with huge debts in the wake of high spending years before the financial crisis, combined with the burden of bailing out broken lenders.
As a result a series of governments have lost top credit ratings – France lots its triple-A rating – and others are on negative outlooks.
But despite their efforts to cut deficits since 2008, the states may never regain their previous status as they are failing to get debts back on a declining path.
“Historically, public debt in Europe has tended to step up after each crisis over the past four decades. A repeat of this outcome remains a possibility despite concerted efforts to prevent it through treaty and legislation.”