Yes, you will need a lawyer or even lawyers, if you find yourself in this kind of trouble. Lawyers, regardless of what they are doing, are doing it to earn their living, among other things. Get ready to pay for the service and remember why you needed the service in the first place.
If a respondent is still trading (not in liquidation) it is open to the claimant to take the claim to arbitration with some prospect of making a recovery.
Sam Goldwyn (of Metro-Goldwyn-Mayer, the US film producers) said of oral contracts, that they were not worth the paper they were written on. He was right, because of the lack of certainty they embody. Inevitably the two interlocutors making the “oral contract” will have differing recollections of the terms agreed. Litigation on such a contract is an unpredictable gamble.
Who, in the name of goodness, does the UK Roads Authority use to write its contracts?
In truth, neither the contractors nor the public authorities seeking tenders genuinely know what the costs of such projects are; the tenders are guesses.
These contracts are very valuable. They allow the person to whom the contract is awarded to, at the very least, pay the wages of the staff of the successful tendering company, say, during slack industry trading periods.
It is important to recognize that the expense of construction (which is considerable) carries the hidden reciprocal cost of the dispute and that the parties should budget for spending that money if and when the dispute breaks out. If that is budgeted for there will be a minimized loss of momentum in driving the dispute resolution process to an early conclusion.