Campaign Trail: "Peter Robinson's face is getting redder," says Gregory Campbell, pointing mischievously to the super-sized image of his Westminster colleague on the side of the DUP Battle Bus.
His comment prompts a closer inspection by the DUP officials accompanying Mr Campbell. They all concur.
But it's not just Peter Robinson. The giant faces of the five DUP MPs which adorn the side of the Battle Bus, including Mr Campbell, have all grown redder since Monday.
The general consensus is that the heat of the bus's engine is to blame.
It's 11.30 a.m. on Wednesday morning and the DUP campaign is outside the Northcott Shopping Centre in Glegormley, on the outskirts of Belfast, the first stop on that morning's tour of the constituency of South Antrim.
The DUP team is in good humour and evidently pleased with their Battle Bus. It's the first time a Northern party has used an election bus, they say. The reaction is positive, especially among the local party candidates and supporters who were there in force in Glengormley to greet the bus.
The Battle Bus is kitted out with two Sony Playstations, which party officials have yet to get working, satellite television and a refreshment bar. The colour scheme is royal blue, naturally.
The bus is in fact the same one used by William Hague during the Conservatives' ill-fated 2001 election campaign, in which the party gained only one seat.
The Battle Bus passengers shudder at the mention of the former Tory leader and his campaign as if they fear it will curse their own campaign.
The party is expecting at least one extra seat in South Antrim alone, according to Gregory Campbell. Sammy Wilson and Mr Campbell are the DUP stars on the bus this morning, there to lend their support to the three South Antrim candidates, Wilson Clyde, Paul Girvan and John Smyth.
During the week, the SDLP leader, Mr Mark Durkan, accused the UUP of being "DUP lite", but back on the bus both Sammy Wilson and Gregory Campbell are doing a fair impression of that themselves.
The DUP's manifesto during this election is possibly the most moderate-sounding ever produced by the Paisleyite party. Gone is the hardline language of No Surrender, to be replaced by one designed to appeal to agreement-sceptic unionists who have traditionally voted for the UUP.
It is part of an aggressive campaign targeted at overtaking the UUP as the largest unionist party in the North. To have even a remote chance of achieving that, the DUP will have to put in very strong performances in constituencies such as South Antrim. Gregory Campbell believes there has been a fundamental shift in which the DUP is now accepted as a mainstream unionist party.
During the 1998 Assembly elections, anti-agreement UUP supporters voted for independent unionist parties because they still could not bring themselves to vote DUP.
"They left the warmth and comfort zone of the UUP in 1998, and went the whole way in 2001, when they found a natural home in the DUP," he says, pointing to the fact that the party took an extra three seats in the Westminster elections.
The change in the DUP's image for mainstream unionists as being a potential party of government has been helped by the impressive performance in Assembly ministerial roles by party members such as Mr Campbell.
Back on the canvass in South Antrim, however, the DUP is encountering the same problem as the other parties. It's November, and voters are thin on the ground.
After Glengormley, the bus moves on to Ballyclare, a market town nestling in the hills of Antrim, and a unionist stronghold to boot. But again there are few shoppers about.
The canvassing styles of the two DUP stars on the bus that day are in marked contrast. Sammy Wilson alights from the bus at breakneck speed, hunting for potential voters, who are treated to large handshakes, with hugs for the ladies, while Gregory Campbell's style is more reserved, to the point of deferential politeness.
If there is any concern about the small numbers, the canvassers don't show it, despite the fact that on the final stop - a shopping precinct in Templepatrick - the 11-strong team of DUP canvassers actually outnumbers the shoppers.
The Battle Bus passengers wax lyrical, however, about the crowds on the previous day, when the "Doc", or the "Big Man" himself, was on the bus for a canvass of Coleraine town centre. "It was like a blood transfusion," Gregory Campbell says of the 77-year-old Dr Paisley's canvass the previous day, going on to do quite a passable impression of the reverend's exhortations to younger canvassers to pick up the pace. Dr Paisley, who has been looking frail in recent months, still retains a legendary status and loyalty among the DUP grassroots.
When the canvass finishes just before 1 p.m., the team is taken to the home of local party official Mel Lucas. There the Lucas family and local DUP women have laid on a huge spread of soup, sandwiches and desserts for the canvassing team.
Before lunch begins, heads are bowed as Mel Lucas says grace, praying for the welfare of Ian Paisley and Peter Robinson.
"The DUP is famous for its spreads," explains a party official back on the bus as it makes its way over the mountains and down into Belfast. "We'll have to work that one off with a good canvass tonight."
The bus is taken on a drive through North and East Belfast on its way back into the city, but some voters just don't get the idea. On Ballysillan Avenue, just around the corner from DUP MP Nigel Dodd's constituency office, an elderly gentleman at a bus-stop tries to wave down the DUP vehicle, mistaking it for an Ulster Bus one.
He is visibly unimpressed when it fails to stop. Sammy Wilson jumps up from his seat with mischief in his eyes. "That's one less vote for Nigel," he says, as the bus makes its way back to the city-centre.