Number 10 said all the Conservative grandee was doing was trying to establish "the resolve" that Theresa May's administration has to defend the sovereignty of the territory.
Ms May also laughed off suggestions Britain was willing to use its military muscle to influence the debate with the EU on Gibraltar, saying it was "jaw jaw not war war" - borrowing a phrase from Winston Churchill.
It came after the Spanish Foreign Minister urged the UK Government to "be cool", following the furore around Lord Howard's comments that Britain would go to war over Gibraltar in the same way it had over the Falklands.
Theresa May's official spokesman said "it isn't going to happen", when asked about the former Tory leader's comments on a potential war with Spain.
But when repeatedly asked if Ms May had found the intervention unhelpful, he said: "All that Lord Howard was trying to establish, was the resolve that we have to protect the rights of Gibraltar and its sovereignty as I have set out.
"We've been very clear that we will support fully Gibraltar's right to its sovereignty."
On Friday morning, European Council President Donald Tusk published his draft guidelines for the forthcoming Brexit negotiations with the EU, which said Spain would be given a veto over any deal that would affect the status of Gibraltar.
The Number 10 spokesman added: "These are draft guidelines that were issued on Friday. We expect the position to come back to us later this month...and obviously we will wait and see what is agreed by the 27 [EU nations]."
Earlier on Monday, Spanish minister Alfonso Dastis said Madrid must have a veto over any agreements made over Gibraltar, which sits on Spain's southern tip and is an important strategic enclave that the country has wanted back since it ceded it to the British more than 300 years ago.
In response to the growing furore in the UK press, he said: "Let's be cool and carry on, and not use too harsh language, I would say. Let's just negotiate. I think that's the most important."
Mr Dastis's comments were similar to those made by Dutch foreign minister Bert Koenders, who called for calm and argued that the Brexit divorce is difficult enough already.
Brexit Secretary David Davis also raised Gibraltar with Spanish counterparts in what Downing Street described as "friendly and constructive" talks in Madrid on Monday.
The Prime Minister was forced at the weekend to reiterate the UK’s “steadfast commitment” to Gibraltar after Lord Howard caused embarrassment by suggesting the UK could go to war with Spain over the territory, as it had done with Argentina over the Falklands.
Mr Howard told Sky News: “Thirty-five years ago this week, another woman prime minister sent a taskforce halfway across the world to defend the freedom of another small group of British people against another Spanish-speaking country, and I’m absolutely certain that our current Prime Minister will show the same resolve in standing by the people of Gibraltar.”
Foreign Secretary Boris Johnson said on Monday: "I think the position of the Government is very, very clear. Which is that the sovereignty of Gibraltar is unchanged and it's not going to change, and cannot conceivably change without the express support and consent of the people of Gibraltar and the United Kingdom."
Gibraltar’s First Minister Fabian Picardo had said the possibility of shared sovereignty with Spain would “strip of us who we are” before adding that “the United Kingdom goes to war over the principle of consent all around the world”.Reuse content